Substring
You are encouraged to solve this task according to the task description, using any language you may know.
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |
Comparison |
Matching
Memory Operations
Pointers & references |
Addresses
In this task display a substring:
- starting from n characters in and of m length;
- starting from n characters in, up to the end of the string;
- whole string minus last character;
- starting from a known character within the string and of m length;
- starting from a known substring within the string and of m length.
If the program uses UTF-8 or UTF-16, it must work on any valid Unicode code point,
whether in the Basic Multilingual Plane or above it.
The program must reference logical characters (code points), not 8-bit code units for UTF-8 or 16-bit code units for UTF-16.
Programs for other encodings (such as 8-bit ASCII, or EUC-JP) are not required to handle all Unicode characters.
AArch64 Assembly
<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program subString64.s */
/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc"
/*******************************************/ /* Initialized data */ /*******************************************/ .data szMessString: .asciz "Result : " szString1: .asciz "abcdefghijklmnopqrstuvwxyz" szStringStart: .asciz "abcdefg" szCarriageReturn: .asciz "\n" /*******************************************/ /* UnInitialized data */ /*******************************************/ .bss szSubString: .skip 500 // buffer result
/*******************************************/ /* code section */ /*******************************************/ .text .global main main:
ldr x0,qAdrszString1 // address input string ldr x1,qAdrszSubString // address output string mov x2,22 // location mov x3,4 // length bl subStringNbChar // starting from n characters in and of m length ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszSubString // display substring result bl affichageMess ldr x0,qAdrszCarriageReturn // display line return bl affichageMess // ldr x0,qAdrszString1 ldr x1,qAdrszSubString mov x2,15 // location bl subStringEnd //starting from n characters in, up to the end of the string ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszSubString bl affichageMess ldr x0,qAdrszCarriageReturn // display line return bl affichageMess // ldr x0,qAdrszString1 ldr x1,qAdrszSubString bl subStringMinus // whole string minus last character ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszSubString bl affichageMess ldr x0,qAdrszCarriageReturn // display line return bl affichageMess // ldr x0,qAdrszString1 ldr x1,qAdrszSubString mov x2,'c' // start character mov x3,5 // length bl subStringStChar //starting from a known character within the string and of m length cmp x0,-1 // error ? beq 2f ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszSubString bl affichageMess ldr x0,qAdrszCarriageReturn // display line return bl affichageMess //
2:
ldr x0,qAdrszString1 ldr x1,qAdrszSubString ldr x2,qAdrszStringStart // sub string to start mov x3,10 // length bl subStringStString // starting from a known substring within the string and of m length cmp x0,-1 // error ? beq 3f ldr x0,qAdrszMessString // display message bl affichageMess ldr x0,qAdrszSubString bl affichageMess ldr x0,qAdrszCarriageReturn // display line return bl affichageMess
3: 100: // standard end of the program
mov x0,0 // return code mov x8,EXIT // request to exit program svc 0 // perform system call
qAdrszMessString: .quad szMessString qAdrszString1: .quad szString1 qAdrszSubString: .quad szSubString qAdrszStringStart: .quad szStringStart qAdrszCarriageReturn: .quad szCarriageReturn /******************************************************************/ /* sub strings index start number of characters */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of the output string */ /* x2 contains the start index */ /* x3 contains numbers of characters to extract */ /* x0 returns number of characters or -1 if error */ subStringNbChar:
stp x1,lr,[sp,-16]! // save registers mov x14,#0 // counter byte output string
1:
ldrb w15,[x0,x2] // load byte string input cbz x15,2f // zero final ? strb w15,[x1,x14] // store byte output string add x2,x2,1 // increment counter add x14,x14,1 cmp x14,x3 // end ? blt 1b // no -> loop
2:
strb wzr,[x1,x14] // store final zero byte string 2 mov x0,x14
100:
ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/******************************************************************/ /* sub strings index start at end of string */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of the output string */ /* x2 contains the start index */ /* x0 returns number of characters or -1 if error */ subStringEnd:
stp x2,lr,[sp,-16]! // save registers mov x14,0 // counter byte output string
1:
ldrb w15,[x0,x2] // load byte string 1 cbz x15,2f // zero final ? strb w15,[x1,x14] add x2,x2,1 add x14,x14,1 b 1b // loop
2:
strb wzr,[x1,x14] // store final zero byte string 2 mov x0,x14
100:
ldp x2,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/******************************************************************/ /* whole string minus last character */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of the output string */ /* x0 returns number of characters or -1 if error */ subStringMinus:
stp x1,lr,[sp,-16]! // save registers mov x12,0 // counter byte input string mov x14,0 // counter byte output string
1:
ldrb w15,[x0,x12] // load byte string cbz x15,2f // zero final ? strb w15,[x1,x14] add x12,x12,1 add x14,x14,1 b 1b // loop
2:
sub x14,x14,1 strb wzr,[x1,x14] // store final zero byte string 2 mov x0,x14
100:
ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/******************************************************************/ /* starting from a known character within the string and of m length */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of the output string */ /* x2 contains the character */ /* x3 contains the length /* x0 returns number of characters or -1 if error */ subStringStChar:
stp x1,lr,[sp,-16]! // save registers mov x16,0 // counter byte input string mov x14,0 // counter byte output string
1:
ldrb w15,[x0,x16] // load byte string cbz x15,4f // zero final ? cmp x15,x2 // character find ? beq 2f // yes add x16,x16,1 // no -> increment indice b 1b // loop
2:
strb w15,[x1,x14] add x16,x16,1 add x14,x14,1 cmp x14,x3 bge 3f ldrb w15,[x0,x16] // load byte string cbnz x15,2b // loop if no zero final
3:
strb wzr,[x1,x14] // store final zero byte string 2 mov x0,x14 b 100f
4:
strb w15,[x1,x14] mov x0,#-1
100:
ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/******************************************************************/ /* starting from a known substring within the string and of m length */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of the output string */ /* x2 contains the address of string to start */ /* x3 contains the length /* x0 returns number of characters or -1 if error */ subStringStString:
stp x1,lr,[sp,-16]! // save registers stp x20,x21,[sp,-16]! // save registers mov x20,x0 // save address mov x21,x1 // save address output string mov x1,x2 bl searchSubString cmp x0,-1 // not found ? beq 100f mov x16,x0 // counter byte input string mov x14,0
1:
ldrb w15,[x20,x16] // load byte string strb w15,[x21,x14] cmp x15,#0 // zero final ? csel x0,x14,x0,eq beq 100f add x14,x14,1 cmp x14,x3 add x15,x16,1 csel x16,x15,x16,lt blt 1b // loop strb wzr,[x21,x14] mov x0,x14 // return indice
100:
ldp x20,x21,[sp],16 // restaur 2 registers ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/******************************************************************/ /* search a substring in the string */ /******************************************************************/ /* x0 contains the address of the input string */ /* x1 contains the address of substring */ /* x0 returns index of substring in string or -1 if not found */ searchSubString:
stp x1,lr,[sp,-16]! // save registers mov x12,0 // counter byte input string mov x13,0 // counter byte string mov x16,-1 // index found ldrb w14,[x1,x13]
1:
ldrb w15,[x0,x12] // load byte string cbz x15,4f // zero final ? cmp x15,x14 // compare character beq 2f mov x16,-1 // no equals - > raz index mov x13,0 // and raz counter byte add x12,x12,1 // and increment counter byte b 1b // and loop
2: // characters equals
cmp x16,-1 // first characters equals ? csel x16,x12,x16,eq // moveq x6,x2 // yes -> index begin in x6 add x13,x13,1 // increment counter substring ldrb w14,[x1,x13] // and load next byte cbz x14,3f // zero final ? yes -> end search add x12,x12,1 // else increment counter string b 1b // and loop
3:
mov x0,x16 // return indice b 100f
4:
mov x0,#-1 // yes returns error
100:
ldp x1,lr,[sp],16 // restaur 2 registers ret // return to address lr x30
/********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc" </lang>
- Output:
Result : wxyz Result : pqrstuvwxyz Result : abcdefghijklmnopqrstuvwxy Result : cdefg Result : abcdefghij
Ada
String in Ada is an array of Character elements indexed by Positive: <lang Ada>type String is array (Positive range <>) of Character;</lang> Substring is a first-class object in Ada, an anonymous subtype of String. The language uses the term slice for it. Slices can be retrieved, assigned and passed as a parameter to subprograms in mutable or immutable mode. A slice is specified as: <lang Ada>A (<first-index>..<last-index>)</lang>
A string array in Ada can start with any positive index. This is why the implementation below uses Str'First in all slices, which in this concrete case is 1, but intentionally left in the code because the task refers to N as an offset to the string beginning rather than an index in the string. In Ada it is unusual to deal with slices in such way. One uses plain string index instead. <lang Ada>with Ada.Text_IO; use Ada.Text_IO; with Ada.Strings.Fixed; use Ada.Strings.Fixed;
procedure Test_Slices is
Str : constant String := "abcdefgh"; N : constant := 2; M : constant := 3;
begin
Put_Line (Str (Str'First + N - 1..Str'First + N + M - 2)); Put_Line (Str (Str'First + N - 1..Str'Last)); Put_Line (Str (Str'First..Str'Last - 1)); Put_Line (Head (Tail (Str, Str'Last - Index (Str, "d", 1)), M)); Put_Line (Head (Tail (Str, Str'Last - Index (Str, "de", 1) - 1), M));
end Test_Slices;</lang>
- Output:
bcd bcdefgh abcdefg efg fgh
Aikido
Aikido uses square brackets for slices. The syntax is [start:end]
.
If you want to use length you have to add to the start.
Shifting strings left or right removes characters from the ends.
<lang aikido> const str = "abcdefg" var n = 2 var m = 3
println (str[n:n+m-1]) // pos 2 length 3 println (str[n:]) // pos 2 to end println (str >> 1) // remove last character var p = find (str, 'c') println (str[p:p+m-1]) // from pos of p length 3
var s = find (str, "bc") println (str[s, s+m-1]) // pos of bc length 3 </lang>
Aime
<lang aime>text s; data b, d;
s = "The quick brown fox jumps over the lazy dog.";
o_text(cut(s, 4, 15)); o_newline(); o_text(cut(s, 4, length(s))); o_newline(); o_text(delete(s, -1)); o_newline(); o_text(cut(s, index(s, 'q'), 5)); o_newline();
b_cast(b, s); b_cast(d, "brown"); o_text(cut(s, b_find(b, d), 15)); o_newline();</lang>
- Output:
quick brown fox quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog quick brown fox jumps
ALGOL 68
<lang Algol68>main: (
STRING s = "abcdefgh"; INT n = 2, m = 3; CHAR char = "d"; STRING chars = "cd";
printf(($gl$, s[n:n+m-1])); printf(($gl$, s[n:])); printf(($gl$, s[:UPB s-1])); INT pos; char in string("d", pos, s); printf(($gl$, s[pos:pos+m-1])); string in string("de", pos, s); printf(($gl$, s[pos:pos+m-1]))
)</lang>
- Output:
bcd bcdefgh abcdefg def def
Apex
In Apex, the substring method returns a new String that begins with the character at the specified zero-based startIndex and extends to the end of the String. <lang apex>String x = 'testing123'; //Test1: testing123 System.debug('Test1: ' + x.substring(0,x.length())); //Test2: esting123 System.debug('Test2: ' + x.substring(1,x.length())); //Test3: testing123 System.debug('Test3: ' + x.substring(0)); //Test4: 3 System.debug('Test4: ' + x.substring(x.length()-1)); //Test5: System.debug('Test5: ' + x.substring(1,1)); //Test 6: testing123 System.debug('Test6: ' + x.substring(x.indexOf('testing'))); //Test7: e System.debug('Test7: ' + x.substring(1,2)); </lang>
AppleScript
Expressed in terms of some familiar functional primitives, so that we can focus more on the task, without too much distraction by the parochial quirks of a particular scripting language.
(Functional primitives version)
<lang AppleScript>-- SUBSTRINGS -----------------------------------------------------------------
-- take :: Int -> Text -> Text on take(n, s)
text 1 thru n of s
end take
-- drop :: Int -> Text -> Text on drop(n, s)
text (n + 1) thru -1 of s
end drop
-- breakOn :: Text -> Text -> (Text, Text) on breakOn(strPattern, s)
set {dlm, my text item delimiters} to {my text item delimiters, strPattern} set lstParts to text items of s set my text item delimiters to dlm {item 1 of lstParts, strPattern & (item 2 of lstParts)}
end breakOn
-- init :: Text -> Text on init(s)
if length of s > 0 then text 1 thru -2 of s else missing value end if
end init
-- TEST -----------------------------------------------------------------------
on run
set str to "一二三四五六七八九十" set legends to {¬ "from n in, of n length", ¬ "from n in, up to end", ¬ "all but last", ¬ "from matching char, of m length", ¬ "from matching string, of m length"} set parts to {¬ take(3, drop(4, str)), ¬ drop(3, str), ¬ init(str), ¬ take(3, item 2 of breakOn("五", str)), ¬ take(4, item 2 of breakOn("六七", str))} script tabulate property strPad : " " on |λ|(l, r) l & drop(length of l, strPad) & r end |λ| end script linefeed & intercalate(linefeed, ¬ zipWith(tabulate, ¬ legends, parts)) & linefeed
end run
-- GENERIC FUNCTIONS FOR TEST -------------------------------------------------
-- intercalate :: Text -> [Text] -> Text on intercalate(strText, lstText)
set {dlm, my text item delimiters} to {my text item delimiters, strText} set strJoined to lstText as text set my text item delimiters to dlm return strJoined
end intercalate
-- min :: Ord a => a -> a -> a on min(x, y)
if y < x then y else x end if
end min
-- Lift 2nd class handler function into 1st class script wrapper -- mReturn :: Handler -> Script on mReturn(f)
if class of f is script then f else script property |λ| : f end script end if
end mReturn
-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] on zipWith(f, xs, ys)
set lng to min(length of xs, length of ys) set lst to {} tell mReturn(f) repeat with i from 1 to lng set end of lst to |λ|(item i of xs, item i of ys) end repeat return lst end tell
end zipWith</lang>
- Output:
from n in, of n length 五六七 from n in, up to end 四五六七八九十 all but last 一二三四五六七八九 from matching char, of m length 五六七 from matching string, of m length 六七八九
ARM Assembly
<lang ARM Assembly>
/* ARM assembly Raspberry PI */ /* program substring.s */
/* Constantes */ .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ WRITE, 4 @ Linux syscall
.equ BUFFERSIZE, 100
/* Initialized data */ .data szMessString: .asciz "Result : " szString1: .asciz "abcdefghijklmnopqrstuvwxyz" szStringStart: .asciz "abcdefg" szCarriageReturn: .asciz "\n"
/* UnInitialized data */ .bss szSubString: .skip 500 @ buffer result
/* code section */
.text
.global main
main:
ldr r0,iAdrszString1 @ address input string ldr r1,iAdrszSubString @ address output string mov r2,#22 @ location mov r3,#4 @ length bl subStringNbChar @ starting from n characters in and of m length ldr r0,iAdrszMessString @ display message bl affichageMess ldr r0,iAdrszSubString @ display substring result bl affichageMess ldr r0,iAdrszCarriageReturn @ display line return bl affichageMess @ ldr r0,iAdrszString1 ldr r1,iAdrszSubString mov r2,#15 @ location bl subStringEnd @starting from n characters in, up to the end of the string ldr r0,iAdrszMessString @ display message bl affichageMess ldr r0,iAdrszSubString bl affichageMess ldr r0,iAdrszCarriageReturn @ display line return bl affichageMess @ ldr r0,iAdrszString1 ldr r1,iAdrszSubString bl subStringMinus @ whole string minus last character ldr r0,iAdrszMessString @ display message bl affichageMess ldr r0,iAdrszSubString bl affichageMess ldr r0,iAdrszCarriageReturn @ display line return bl affichageMess @ ldr r0,iAdrszString1 ldr r1,iAdrszSubString mov r2,#'c' @ start character mov r3,#5 @ length bl subStringStChar @starting from a known character within the string and of m length cmp r0,#-1 @ error ? beq 2f ldr r0,iAdrszMessString @ display message bl affichageMess ldr r0,iAdrszSubString bl affichageMess ldr r0,iAdrszCarriageReturn @ display line return bl affichageMess @
2:
ldr r0,iAdrszString1 ldr r1,iAdrszSubString ldr r2,iAdrszStringStart @ sub string to start mov r3,#10 @ length bl subStringStString @ starting from a known substring within the string and of m length cmp r0,#-1 @ error ? beq 3f ldr r0,iAdrszMessString @ display message bl affichageMess ldr r0,iAdrszSubString bl affichageMess ldr r0,iAdrszCarriageReturn @ display line return bl affichageMess
3: 100: @ standard end of the program
mov r0, #0 @ return code mov r7, #EXIT @ request to exit program svc 0 @ perform system call
iAdrszMessString: .int szMessString iAdrszString1: .int szString1 iAdrszSubString: .int szSubString iAdrszStringStart: .int szStringStart iAdrszCarriageReturn: .int szCarriageReturn /******************************************************************/ /* sub strings index start number of characters */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of the output string */ /* r2 contains the start index */ /* r3 contains numbers of characters to extract */ /* r0 returns number of characters or -1 if error */ subStringNbChar:
push {r1-r5,lr} @ save registers mov r4,#0 @ counter byte output string
1:
ldrb r5,[r0,r2] @ load byte string input cmp r5,#0 @ zero final ? beq 2f strb r5,[r1,r4] @ store byte output string add r2,#1 @ increment counter add r4,#1 cmp r4,r3 @ end ? blt 1b @ no -> loop
2:
mov r5,#0 strb r5,[r1,r4] @ load byte string 2 mov r0,r4
100:
pop {r1-r5,lr} @ restaur registers bx lr @ return
/******************************************************************/ /* sub strings index start at end of string */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of the output string */ /* r2 contains the start index */ /* r0 returns number of characters or -1 if error */ subStringEnd:
push {r1-r5,lr} @ save registers mov r4,#0 @ counter byte output string
1:
ldrb r5,[r0,r2] @ load byte string 1 cmp r5,#0 @ zero final ? beq 2f strb r5,[r1,r4] add r2,#1 add r4,#1 b 1b @ loop
2:
mov r5,#0 strb r5,[r1,r4] @ load byte string 2 mov r0,r4
100:
pop {r1-r5,lr} @ restaur registers bx lr
/******************************************************************/ /* whole string minus last character */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of the output string */ /* r0 returns number of characters or -1 if error */ subStringMinus:
push {r1-r5,lr} @ save registers mov r2,#0 @ counter byte input string mov r4,#0 @ counter byte output string
1:
ldrb r5,[r0,r2] @ load byte string cmp r5,#0 @ zero final ? beq 2f strb r5,[r1,r4] add r2,#1 add r4,#1 b 1b @ loop
2:
sub r4,#1 mov r5,#0 strb r5,[r1,r4] @ load byte string 2 mov r0,r4
100:
pop {r1-r5,lr} @ restaur registers bx lr
/******************************************************************/ /* starting from a known character within the string and of m length */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of the output string */ /* r2 contains the character */ /* r3 contains the length /* r0 returns number of characters or -1 if error */ subStringStChar:
push {r1-r5,lr} @ save registers mov r6,#0 @ counter byte input string mov r4,#0 @ counter byte output string
1:
ldrb r5,[r0,r6] @ load byte string cmp r5,#0 @ zero final ? streqb r5,[r1,r4] moveq r0,#-1 beq 100f cmp r5,r2 beq 2f add r6,#1 b 1b @ loop
2:
strb r5,[r1,r4] add r6,#1 add r4,#1 cmp r4,r3 bge 3f ldrb r5,[r0,r6] @ load byte string cmp r5,#0 bne 2b
3:
mov r5,#0 strb r5,[r1,r4] @ load byte string 2 mov r0,r4
100:
pop {r1-r5,lr} @ restaur registers bx lr
/******************************************************************/ /* starting from a known substring within the string and of m length */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of the output string */ /* r2 contains the address of string to start */ /* r3 contains the length /* r0 returns number of characters or -1 if error */ subStringStString:
push {r1-r8,lr} @ save registers mov r7,r0 @ save address mov r8,r1 @ counter byte string mov r1,r2 bl searchSubString cmp r0,#-1 beq 100f mov r6,r0 @ counter byte input string mov r4,#0
1:
ldrb r5,[r7,r6] @ load byte string strb r5,[r8,r4] cmp r5,#0 @ zero final ? moveq r0,r4 beq 100f add r4,#1 cmp r4,r3 addlt r6,#1 blt 1b @ loop mov r5,#0 strb r5,[r8,r4] mov r0,r4
100:
pop {r1-r8,lr} @ restaur registers bx lr
/******************************************************************/ /* search a substring in the string */ /******************************************************************/ /* r0 contains the address of the input string */ /* r1 contains the address of substring */ /* r0 returns index of substring in string or -1 if not found */ searchSubString:
push {r1-r6,lr} @ save registers mov r2,#0 @ counter byte input string mov r3,#0 @ counter byte string mov r6,#-1 @ index found ldrb r4,[r1,r3]
1:
ldrb r5,[r0,r2] @ load byte string cmp r5,#0 @ zero final ? moveq r0,#-1 @ yes returns error beq 100f cmp r5,r4 @ compare character beq 2f mov r6,#-1 @ no equals - > raz index mov r3,#0 @ and raz counter byte add r2,#1 @ and increment counter byte b 1b @ and loop
2: @ characters equals
cmp r6,#-1 @ first characters equals ? moveq r6,r2 @ yes -> index begin in r6 add r3,#1 @ increment counter substring ldrb r4,[r1,r3] @ and load next byte cmp r4,#0 @ zero final ? beq 3f @ yes -> end search add r2,#1 @ else increment counter string b 1b @ and loop
3:
mov r0,r6
100:
pop {r1-r6,lr} @ restaur registers bx lr
/******************************************************************/ /* display text with size calculation */ /******************************************************************/ /* r0 contains the address of the message */ affichageMess:
push {r0,r1,r2,r7,lr} @ save registers mov r2,#0 @ counter length */
1: @ loop length calculation
ldrb r1,[r0,r2] @ read octet start position + index cmp r1,#0 @ if 0 its over addne r2,r2,#1 @ else add 1 in the length bne 1b @ and loop @ so here r2 contains the length of the message mov r1,r0 @ address message in r1 mov r0,#STDOUT @ code to write to the standard output Linux mov r7, #WRITE @ code call system "write" svc #0 @ call system pop {r0,r1,r2,r7,lr} @ restaur registers bx lr @ return
</lang>
Arturo
<lang arturo>s: "abcdefgh" n: 2 m: 3 c: "d" cs: "cd"
// starting from n=2 characters in and m=3 in length print [slice s n-1 n+m-2]
// starting from n characters in, up to the end of the string print [slice s n-1]
// whole string minus last character print [slice s 0 [size s]-2]
// starting from a known character c='d' within the string and of m length i: index s c print [slice s i i+m-1]
// starting from a known substring cs="cd" within the string and of m length i: index s cs print [slice s i i+m-1] </lang>
- Output:
bcd bcdefgh abcdefg def cde
AutoHotkey
The code contains some alternatives. <lang autohotkey>String := "abcdefghijklmnopqrstuvwxyz"
- also
- String = abcdefghijklmnopqrstuvwxyz
n := 12 m := 5
- starting from n characters in and of m length;
subString := SubStr(String, n, m)
- alternative
- StringMid, subString, String, n, m
MsgBox % subString
- starting from n characters in, up to the end of the string;
subString := SubStr(String, n)
- alternative
- StringMid, subString, String, n
MsgBox % subString
- whole string minus last character;
StringTrimRight, subString, String, 1
- alternatives
- subString := SubStr(String, 1, StrLen(String) - 1)
- StringMid, subString, String, 1, StrLen(String) - 1
MsgBox % subString
- starting from a known character within the string and of m length;
findChar := "q" subString := SubStr(String, InStr(String, findChar), m)
- alternatives
- RegExMatch(String, findChar . ".{" . m - 1 . "}", subString)
- StringMid, subString, String, InStr(String, findChar), m
MsgBox % subString
- starting from a known character within the string and of m length;
findString := "pq" subString := SubStr(String, InStr(String, findString), m)
- alternatives
- RegExMatch(String, findString . ".{" . m - StrLen(findString) . "}", subString)
- StringMid, subString, String, InStr(String, findString), m
MsgBox % subString </lang>
- Output:
lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy qrstu pqrst
AWK
<lang awk>BEGIN { str = "abcdefghijklmnopqrstuvwxyz" n = 12 m = 5
print substr(str, n, m) print substr(str, n) print substr(str, 1, length(str) - 1) print substr(str, index(str, "q"), m) print substr(str, index(str, "pq"), m) }</lang>
- Output:
$ awk -f substring.awk lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy qrstu pqrst
Axe
<lang axe>Lbl SUB1 0→{r₁+r₂+r₃} r₁+r₂ Return
Lbl SUB2 r₁+r₂ Return
Lbl SUB3 0→{r₁+length(r₁)-1} r₁ Return
Lbl SUB4 inData(r₂,r₁)-1→I 0→{r₁+I+r₃} r₁+I Return</lang>
BASIC
<lang qbasic>DIM baseString AS STRING, subString AS STRING, findString AS STRING DIM m AS INTEGER, n AS INTEGER
baseString = "abcdefghijklmnopqrstuvwxyz" n = 12 m = 5
' starting from n characters in and of m length; subString = MID$(baseString, n, m) PRINT subString
' starting from n characters in, up to the end of the string; subString = MID$(baseString, n) PRINT subString
' whole string minus last character; subString = LEFT$(baseString, LEN(baseString) - 1) PRINT subString
' starting from a known character within the string and of m length; ' starting from a known substring within the string and of m length. findString = "pq" subString = MID$(baseString, INSTR(baseString, findString), m) PRINT subString </lang>
- Output:
lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy pqrst
Commodore BASIC
<lang basic>10 REM SUBSTRING ... ROSETTACODE.ORG 20 A$ = "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG" 30 X$ = "J" : S$ = "FOX" 40 N = 5: M = 11 50 PRINT "THE STRING:" 60 PRINT A$ 70 PRINT 80 PRINT "SUBSTRING STARTING FROM" N "CHARACTERS IN AND OF" M "LENGTH:" 90 PRINT MID$(A$,N,M) 100 PRINT 110 PRINT "STARTING FROM" N "CHARACTERS IN, UP TO THE END OF THE STRING:" 120 PRINT RIGHT$(A$,LEN(A$)+1-N) 130 PRINT 140 PRINT "WHOLE STRING MINUS LAST CHARACTER:" 150 PRINT LEFT$(A$,LEN(A$)-1) 160 PRINT 170 PRINT "STARTING FROM '";X$;"' AND OF" M "LENGTH:" 180 I = 1 190 IF MID$(A$,I,1)=X$ THEN 220 200 I = I+1 210 GOTO 190 220 PRINT RIGHT$(A$,LEN(A$)+1-I) 230 PRINT 240 PRINT "STARTING FROM '";S$;"' AND OF" M "LENGTH:" 250 I = 1 260 IF MID$(A$,I,LEN(S$))=S$ THEN 290 270 I = I+1 280 GOTO 260 290 PRINT RIGHT$(A$,LEN(A$)+1-I) 300 END</lang>
- Output:
THE STRING: THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG SUBSTRING STARTING FROM 5 CHARACTERS IN AND OF 11 LENGTH: QUICK BROWN STARTING FROM 5 CHARACTERS IN, UP TO THE END OF THE STRING: QUICK BROWN FOX JUMPS OVER THE LAZY DOG WHOLE STRING MINUS LAST CHARACTER: THE QUICK BROWN FOX JUMPS OVER THE LAZY DO STARTING FROM 'J' AND OF 11 LENGTH: JUMPS OVER THE LAZY DOG STARTING FROM 'FOX' AND OF 11 LENGTH: FOX JUMPS OVER THE LAZY DOG
IS-BASIC
<lang IS-BASIC>100 LET A$="abcdefghijklmnopqrstuvwxyz" 110 LET N=10:LET M=7 120 PRINT A$(N:N+M-1) 130 PRINT A$(N:) 140 PRINT A$(:LEN(A$)-1) 150 LET I=POS(A$,"g") 160 PRINT A$(I:I+M-1) 170 LET I=POS(A$,"ijk") 180 PRINT A$(I:I+M-1)</lang>
ZX Spectrum Basic
ZX Spectrum Basic has unfortunately no direct way to find a substring within a string, however a similar effect can be done searching with a for loop: <lang zxbasic>10 LET A$="abcdefghijklmnopqrstuvwxyz" 15 LET n=10: LET m=7 20 PRINT A$(n TO n+m-1) 30 PRINT A$(n TO ) 40 PRINT A$( TO LEN (A$)-1) 50 FOR i=1 TO LEN (A$) 60 IF A$(i)="g" THEN PRINT A$(i TO i+m-1): LET i=LEN (A$): GO TO 70 70 NEXT i 80 LET B$="ijk" 90 FOR i=1 TO LEN (A$)-LEN (B$)+1 100 IF A$(i TO i+LEN (B$)-1)=B$ THEN PRINT A$(i TO i+m-1): LET i=LEN (A$)-LEN (B$)+1: GO TO 110 110 NEXT i 120 STOP </lang>
Without superfluous code: <lang zxbasic>10 LET A$="abcdefghijklmnopqrstuvwxyz": LET la=LEN A$ 20 LET n=10: LET m=7 30 PRINT A$(n TO n+m-1) 40 PRINT A$(n TO ) 50 PRINT A$( TO la-1) 60 FOR i=1 TO la 70 IF A$(i)="g" THEN PRINT A$(i TO i+m-1): LET i=la 80 NEXT i 90 LET B$="ijk": LET lb=LEN b$ 100 FOR i=1 TO la-lb+1 110 IF A$(i TO i+lb-1)=B$ THEN PRINT A$(i TO i+m-1): LET i=la-lb+1 120 NEXT i</lang>
- Output:
jklmnop jklmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy ghijklm ijklmno
BBC BASIC
<lang bbcbasic> basestring$ = "The five boxing wizards jump quickly"
n% = 10 m% = 5 REM starting from n characters in and of m length: substring$ = MID$(basestring$, n%, m%) PRINT substring$ REM starting from n characters in, up to the end of the string: substring$ = MID$(basestring$, n%) PRINT substring$ REM whole string minus last character: substring$ = LEFT$(basestring$) PRINT substring$ REM starting from a known character within the string and of m length: char$ = "w" substring$ = MID$(basestring$, INSTR(basestring$, char$), m%) PRINT substring$ REM starting from a known substring within the string and of m length: find$ = "iz" substring$ = MID$(basestring$, INSTR(basestring$, find$), m%) PRINT substring$</lang>
- Output:
boxin boxing wizards jump quickly The five boxing wizards jump quickl wizar izard
Bracmat
<lang bracmat>( (basestring = "The five boxing wizards jump quickly") & (n = 10) & (m = 5)
{ starting from n characters in and of m length: }
& @(!basestring:? [(!n+-1) ?substring [(!n+!m+-1) ?) & out$!substring
{ starting from n characters in, up to the end of the string: }
& @(!basestring:? [(!n+-1) ?substring) & out$!substring
{ whole string minus last character: }
& @(!basestring:?substring [-2 ?) & out$!substring
{ starting from a known character within the string and of m length: }
& (char = "w") & @(!basestring:? ([?p !char ?: ?substring [(!p+!m) ?)) & out$!substring
{ starting from a known substring within the string and of m length: }
& (find = "iz") & @(!basestring:? ([?p !find ?: ?substring [(!p+!m) ?)) & out$!substring & )</lang>
- Output:
boxin boxing wizards jump quickly The five boxing wizards jump quickl wizar izard
Burlesque
<lang blsq> blsq ) "RosettaCode"5.+ "Roset" blsq ) "RosettaCode"5.+2.- "set" blsq ) "RosettaCode""set"ss 2 blsq ) "RosettaCode"J"set"ss.- "settaCode" blsq ) "RosettaCode"~] "RosettaCod" blsq ) "RosettaCode"[- "osettaCode" </lang>
Selecting/Deleting individual characters
<lang blsq> blsq ) "RosettaCode"{0 1 3 5}si "Roet" blsq ) "RosettaCode"{0 1 3 5}di "oetaCde" </lang>
C
C: ASCII version
<lang C>/*
* RosettaCode: Substring, C89 * * In this task display a substring: starting from n characters in and of m * length; starting from n characters in, up to the end of the string; whole * string minus last character; starting from a known character within the * string and of m length; starting from a known substring within the string * and of m length. * * This example program DOES NOT make substrings. The program simply displays * certain parts of the input string. * */
- define _CRT_SECURE_NO_WARNINGS /* MSVS compilers need this */
- include <stdio.h>
- include <stdlib.h>
- include <string.h>
/*
* Put no more than m characters from string to standard output. * * It is worth noting that printf("%*s",width,string) does not limit the number * of characters to be printed. * * @param string null terminated string * @param m number of characters to display */
void putm(char* string, size_t m) {
while(*string && m--) putchar(*string++);
}
int main(void) {
char string[] = "Programs for other encodings (such as 8-bit ASCII, or EUC-JP)."
int n = 3; int m = 4; char knownCharacter = '('; char knownSubstring[] = "encodings";
putm(string+n-1, m ); putchar('\n'); puts(string+n+1); putchar('\n'); putm(string, strlen(string)-1); putchar('\n'); putm(strchr(string, knownCharacter), m ); putchar('\n'); putm(strstr(string, knownSubstring), m ); putchar('\n');
return EXIT_SUCCESS;
}</lang>
C: Unicode version
<lang c>/*
* RosettaCode: Substring, C89, Unicode * * In this task display a substring: starting from n characters in and of m * length; starting from n characters in, up to the end of the string; whole * string minus last character; starting from a known character within the * string and of m length; starting from a known substring within the string * and of m length. * * This example program DOES NOT make substrings. The program simply displays * certain parts of the input string. * */
- include <stdio.h>
- include <stdlib.h>
- include <string.h>
/*
* Put all characters from string to standard output AND write newline. * BTW, _putws may not be avaliable. */
void put(wchar_t* string) {
while(*string) putwchar(*string++); putwchar(L'\n');
}
/*
* Put no more than m characters from string to standard output AND newline. */
void putm(wchar_t* string, size_t m) {
while(*string && m--) putwchar(*string++); putwchar(L'\n');
}
int main(void) {
wchar_t string[] = L"Programs for other encodings (such as 8-bit ASCII).";
int n = 3; int m = 4; wchar_t knownCharacter = L'('; wchar_t knownSubstring[] = L"encodings";
putm(string+n-1,m); put (string+n+1); putm(string, wcslen(string)-1); putm(wcschr(string, knownCharacter), m ); putm(wcsstr(string, knownSubstring), m );
return EXIT_SUCCESS;
}</lang>
C: another version
<lang c>#include <stddef.h>
- include <stdio.h>
- include <stdlib.h>
- include <string.h>
char *substring(const char *s, size_t n, ptrdiff_t m) {
char *result; /* check for null s */ if (NULL == s) return NULL; /* negative m to mean 'up to the mth char from right' */ if (m < 0) m = strlen(s) + m - n + 1;
/* n < 0 or m < 0 is invalid */ if (n < 0 || m < 0) return NULL;
/* make sure string does not end before n * and advance the "s" pointer to beginning of substring */ for ( ; n > 0; s++, n--) if (*s == '\0') /* string ends before n: invalid */ return NULL;
result = malloc(m+1); if (NULL == result) /* memory allocation failed */ return NULL; result[0]=0; strncat(result, s, m); /* strncat() will automatically add null terminator * if string ends early or after reading m characters */ return result;
}
char *str_wholeless1(const char *s) {
return substring(s, 0, strlen(s) - 1);
}
char *str_fromch(const char *s, int ch, ptrdiff_t m) {
return substring(s, strchr(s, ch) - s, m);
}
char *str_fromstr(const char *s, char *in, ptrdiff_t m) {
return substring(s, strstr(s, in) - s , m);
}
- define TEST(A) do { \
char *r = (A); \ if (NULL == r) \ puts("--error--"); \ else { \ puts(r); \ free(r); \ } \ } while(0)
int main() {
const char *s = "hello world shortest program";
TEST( substring(s, 12, 5) ); // get "short" TEST( substring(s, 6, -1) ); // get "world shortest program" TEST( str_wholeless1(s) ); // "... progra" TEST( str_fromch(s, 'w', 5) ); // "world" TEST( str_fromstr(s, "ro", 3) ); // "rog"
return 0;
}</lang>
C++
<lang cpp>#include <iostream>
- include <string>
int main() {
std::string s = "0123456789";
int const n = 3; int const m = 4; char const c = '2'; std::string const sub = "456";
std::cout << s.substr(n, m)<< "\n"; std::cout << s.substr(n) << "\n"; std::cout << s.substr(0, s.size()-1) << "\n"; std::cout << s.substr(s.find(c), m) << "\n"; std::cout << s.substr(s.find(sub), m) << "\n";
}</lang>
C_sharp
<lang csharp>using System; namespace SubString {
class Program { static void Main(string[] args) { string s = "0123456789"; const int n = 3; const int m = 2; const char c = '3'; const string z = "345";
Console.WriteLine(s.Substring(n, m)); Console.WriteLine(s.Substring(n, s.Length - n)); Console.WriteLine(s.Substring(0, s.Length - 1)); Console.WriteLine(s.Substring(s.IndexOf(c,0,s.Length), m)); Console.WriteLine(s.Substring(s.IndexOf(z, 0, s.Length), m)); } }
} </lang>
Clojure
<lang lisp>
(def string "alphabet") (def n 2) (def m 4) (def len (count string))
- starting from n characters in and of m length;
(println
(subs string n (+ n m))) ;phab
- starting from n characters in, up to the end of the string;
(println
(subs string n)) ;phabet
- whole string minus last character;
(println
(subs string 0 (dec len))) ;alphabe
- starting from a known character within the string and of m length;
(let [pos (.indexOf string (int \l))]
(println (subs string pos (+ pos m)))) ;lpha
- starting from a known substring within the string and of m length.
(let [pos (.indexOf string "ph")]
(println (subs string pos (+ pos m)))) ;phab
</lang>
COBOL
<lang COBOL> identification division.
program-id. substring.
environment division. configuration section. repository. function all intrinsic.
data division. working-storage section. 01 original. 05 value "this is a string". 01 starting pic 99 value 3. 01 width pic 99 value 8. 01 pos pic 99. 01 ender pic 99. 01 looking pic 99. 01 indicator pic x. 88 found value high-value when set to false is low-value. 01 look-for pic x(8).
procedure division. substring-main.
display "Original |" original "|, n = " starting " m = " width display original(starting : width) display original(starting :) display original(1 : length(original) - 1)
move "a" to look-for move 1 to looking perform find-position if found display original(pos : width) end-if
move "is a st" to look-for move length(trim(look-for)) to looking perform find-position if found display original(pos : width) end-if goback.
find-position. set found to false compute ender = length(original) - looking perform varying pos from 1 by 1 until pos > ender if original(pos : looking) equal look-for then set found to true exit perform end-if end-perform .
end program substring.</lang>
- Output:
prompt$ cobc -xj substring.cob Original |this is a string|, n = 03 m = 08 is is a is is a string this is a strin a string is a str
ColdFusion
Classic tag based CFML
<lang cfm> <cfoutput> <cfset str = "abcdefg"> <cfset n = 2> <cfset m = 3>
#mid( str, n, m )# <cfset countFromRight = Len( str ) - n + 1> #right( str, countFromRight )# <cfset allButLast = Len( str ) - 1> #left( str, allButLast )# <cfset startingIndex = find( "b", str )> #mid( str, startingIndex, m )# <cfset startingIndexSubString = find( "bc", str )> #mid( str, startingIndexSubString, m )#
</cfoutput> </lang>
- Output:
bcd bcdefg abcdef bcd bcd
Script Based CFML
<lang cfm><cfscript> str="abcdefg"; n = 2; m = 3;
// Note: In CF index starts at 1 rather than 0 // starting from n characters in and of m length writeOutput( mid( str, n, m ) ); // starting from n characters in, up to the end of the string countFromRight = Len( str ) - n + 1; writeOutput( right( str, countFromRight ) ); // whole string minus last character allButLast = Len( str ) - 1; writeOutput( left( str, allButLast ) ); // starting from a known character within the string and of m length startingIndex = find( "b", str ); writeOutput( mid( str, startingIndex, m ) ); // starting from a known substring within the string and of m length startingIndexSubString = find( "bc", str ); writeOutput( mid( str, startingIndexSubString, m ) ); </cfscript></lang>
- Output:
bcd bcdefg abcdef bcd bcd
Common Lisp
<lang lisp>(let ((string "0123456789")
(n 2) (m 3) (start #\5) (substring "34")) (list (subseq string n (+ n m)) (subseq string n) (subseq string 0 (1- (length string))) (let ((pos (position start string))) (subseq string pos (+ pos m))) (let ((pos (search substring string))) (subseq string pos (+ pos m)))))</lang>
Component Pascal
BlackBox Component Builder <lang oberon2> MODULE Substrings; IMPORT StdLog,Strings;
PROCEDURE Do*; CONST aStr = "abcdefghijklmnopqrstuvwxyz"; VAR str: ARRAY 128 OF CHAR; pos: INTEGER; BEGIN Strings.Extract(aStr,3,10,str); StdLog.String("from 3, 10 characters:> ");StdLog.String(str);StdLog.Ln; Strings.Extract(aStr,3,LEN(aStr) - 3,str); StdLog.String("from 3, until the end:> ");StdLog.String(str);StdLog.Ln; Strings.Extract(aStr,0,LEN(aStr) - 1,str); StdLog.String("whole string but last:> ");StdLog.String(str);StdLog.Ln; Strings.Find(aStr,'d',0,pos); Strings.Extract(aStr,pos + 1,10,str); StdLog.String("from 'd', 10 characters:> ");StdLog.String(str);StdLog.Ln; Strings.Find(aStr,"de",0,pos); Strings.Extract(aStr,pos + LEN("de"),10,str); StdLog.String("from 'de', 10 characters:> ");StdLog.String(str);StdLog.Ln; END Do;
END Substrings.
</lang>
Execute: ^Q Substrings.Do
- Output:
from 3, 10 characters:> defghijklm from 3, until the end:> defghijklmnopqrstuvwxyz whole string but last:> abcdefghijklmnopqrstuvwxy from 'd', 10 characters:> efghijklmn from 'de', 10 characters:> fghijklmno
Crystal
<lang crystal>def substring_demo(string, n, m, known_character, known_substring)
n -= 1
puts string[n...n+m]
puts string[n...]
puts string.rchop
known_character_index = string.index(known_character).not_nil! puts string[known_character_index...known_character_index+m]
known_substring_index = string.index(known_substring).not_nil! puts string[known_substring_index...known_substring_index+m]
end
substring_demo("crystalline", 3, 5, 't', "st")</lang>
- Output:
ystal ystalline crystallin talli stall
D
<lang d>import std.stdio, std.string;
void main() {
const s = "the quick brown fox jumps over the lazy dog"; enum n = 5, m = 3;
writeln(s[n .. n + m]);
writeln(s[n .. $]);
writeln(s[0 .. $ - 1]);
const i = s.indexOf("q"); writeln(s[i .. i + m]);
const j = s.indexOf("qu"); writeln(s[j .. j + m]);
}</lang>
- Output:
uic uick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog qui qui
Delphi
<lang Delphi>program ShowSubstring;
{$APPTYPE CONSOLE}
uses SysUtils;
const
s = '0123456789'; n = 3; m = 4; c = '2'; sub = '456';
begin
Writeln(Copy(s, n, m)); // starting from n characters in and of m length; Writeln(Copy(s, n, Length(s))); // starting from n characters in, up to the end of the string; Writeln(Copy(s, 1, Length(s) - 1)); // whole string minus last character; Writeln(Copy(s, Pos(c, s), m)); // starting from a known character within the string and of m length; Writeln(Copy(s, Pos(sub, s), m)); // starting from a known substring within the string and of m length.
end.</lang>
- Output:
2345 23456789 012345678 2345 4567
E
<lang e>def string := "aardvarks" def n := 4 def m := 4 println(string(n, n + m)) println(string(n)) println(string(0, string.size() - 1)) println({string(def i := string.indexOf1('d'), i + m)}) println({string(def i := string.startOf("ard"), i + m)})</lang>
- Output:
vark varks aardvark dvar ardv
EasyLang
<lang>a$ = "2019-05-22 22:54:22" print substr a$ 11 5 print substr a$ 11 -1</lang>
22:54 22:54:22
ECL
<lang ECL> /* In this task display a substring:
1. starting from n characters in and of m length; 2. starting from n characters in, up to the end of the string; 3. whole string minus last character; 4. starting from a known character within the string and of m length; 5. starting from a known substring within the string and of m length.
- /
IMPORT STD; //imports a standard string library
TheString := 'abcdefghij'; CharIn := 3; //n StrLength := 4; //m KnownChar := 'f'; KnownSub := 'def'; FindKnownChar := STD.Str.Find(TheString, KnownChar,1); FindKnownSub := STD.Str.Find(TheString, KnownSub,1);
OUTPUT(TheString[Charin..CharIn+StrLength-1]); //task1 OUTPUT(TheString[Charin..]); //task2 OUTPUT(TheString[1..LENGTH(TheString)-1]); //task3 OUTPUT(TheString[FindKnownChar..FindKnownChar+StrLength-1]);//task4 OUTPUT(TheString[FindKnownSub..FindKnownSub+StrLength-1]); //task5
/* OUTPUTS:
defg cdefghij abcdefghi fghi defg
- /
</lang>
Eero
<lang objc>#import <Foundation/Foundation.h>
int main()
autoreleasepool str := 'abcdefgh' n := 2 m := 3 Log( '%@', str[0 .. str.length-1] ) // abcdefgh Log( '%@', str[n .. m] ) // cd Log( '%@', str[n .. str.length-1] ) // cdefgh Log( '%@', str.substringFromIndex: n ) // cdefgh Log( '%@', str[(str.rangeOfString:'b').location .. m] ) // bcd return 0</lang>
Elena
ELENA 4.x : <lang elena>import extensions;
public program() {
var s := "0123456789"; var n := 3; var m := 2; var c := $51; var z := "345"; console.writeLine(s.Substring(n, m)); console.writeLine(s.Substring(n, s.Length - n)); console.writeLine(s.Substring(0, s.Length - 1)); console.writeLine(s.Substring(s.indexOf(0, c), m)); console.writeLine(s.Substring(s.indexOf(0, z), m))
}</lang>
- Output:
34 3456789 012345678 34 34
Elixir
<lang elixir>s = "abcdefgh" String.slice(s, 2, 3) #=> "cde" String.slice(s, 1..3) #=> "bcd" String.slice(s, -3, 2) #=> "fg" String.slice(s, 3..-1) #=> "defgh"
- UTF-8
s = "αβγδεζηθ" String.slice(s, 2, 3) #=> "γδε" String.slice(s, 1..3) #=> "βγδ" String.slice(s, -3, 2) #=> "ζη" String.slice(s, 3..-1) #=> "δεζηθ"</lang>
Erlang
Interactive session in Erlang shell showing built in functions doing the task.
1> N = 3. 2> M = 5. 3> string:sub_string( "abcdefghijklm", N ). "cdefghijklm" 4> string:sub_string( "abcdefghijklm", N, N + M - 1 ). "cdefg" 6> string:sub_string( "abcdefghijklm", 1, string:len("abcdefghijklm") - 1 ). "abcdefghijkl" 7> Start_character = string:chr( "abcdefghijklm", $e ). 8> string:sub_string( "abcdefghijklm", Start_character, Start_character + M - 1 ). "efghi" 9> Start_string = string:str( "abcdefghijklm", "efg" ). 10> string:sub_string( "abcdefghijklm", Start_string, Start_string + M - 1 ). "efghi"
Euphoria
<lang Euphoria>sequence baseString, subString, findString integer findChar integer m, n
baseString = "abcdefghijklmnopqrstuvwxyz"
-- starting from n characters in and of m length; n = 12 m = 5 subString = baseString[n..n+m-1] puts(1, subString ) puts(1,'\n')
-- starting from n characters in, up to the end of the string; n = 12 subString = baseString[n..$] puts(1, subString ) puts(1,'\n')
-- whole string minus last character; subString = baseString[1..$-1] puts(1, subString ) puts(1,'\n')
-- starting from a known character within the string and of m length; findChar = 'o' m = 5 n = find(findChar,baseString) subString = baseString[n..n+m-1] puts(1, subString ) puts(1,'\n')
-- starting from a known substring within the string and of m length. findString = "pq" m = 5 n = match(findString,baseString) subString = baseString[n..n+m-1] puts(1, subString ) puts(1,'\n')</lang>
- Output:
lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy opqrs pqrst
F#
<lang fsharp>[<EntryPoint>] let main args =
let s = "一二三四五六七八九十" let n, m = 3, 2 let c = '六' let z = "六七八"
printfn "%s" (s.Substring(n, m)) printfn "%s" (s.Substring(n)) printfn "%s" (s.Substring(0, s.Length - 1)) printfn "%s" (s.Substring(s.IndexOf(c), m)) printfn "%s" (s.Substring(s.IndexOf(z), m)) 0</lang>
- Output:
四五 四五六七八九十 一二三四五六七八九 六七 六七
Factor
<lang factor>USING: math sequences kernel ;
! starting from n characters in and of m length
- subseq* ( from length seq -- newseq ) [ over + ] dip subseq ;
! starting from n characters in, up to the end of the string
- dummy ( seq n -- tailseq ) tail ;
! whole string minus last character
- dummy1 ( seq -- headseq ) but-last ;
USING: fry sequences kernel ; ! helper word
- subseq-from-* ( subseq len seq quot -- seq ) [ nip ] prepose 2keep subseq* ; inline
! starting from a known character within the string and of m length;
- subseq-from-char ( char len seq -- seq ) [ index ] subseq-from-* ;
! starting from a known substring within the string and of m length.
- subseq-from-seq ( subseq len seq -- seq ) [ start ] subseq-from-* ;</lang>
Falcon
VBA/Python programmer's approach not sure if it's the most falconic way <lang falcon> /* created by Aykayayciti Earl Lamont Montgomery April 9th, 2018 */ s = "FalconPL is not just a multi-paradign language but also fun" n = 12 m = 5
> "starting from n characters in and of m length: ", s[n:n+m] > "starting from n characters in, up to the end of the string: ", s[n:] > "whole string minus last character: ", s[0:len(s)-1] new_n = s.find("j", 0) > "starting from a known character within the string and of m length: ", s[new_n:new_n+m] new_n = s.find("mu", 0) > "starting from a known character within the string and of m length: ", s[new_n:new_n+m] </lang>
- Output:
starting from n characters in and of m length: not j starting from n characters in, up to the end of the string: not just a multi-paradign language but also fun whole string minus last character: FalconPL is not just a multi-paradign language but also fu starting from a known character within the string and of m length: just starting from a known character within the string and of m length: multi [Finished in 2.3s]
Forth
/STRING and SEARCH are standard words. SCAN is widely implemented. Substrings represented by address/length pairs require neither mutation nor allocation.
<lang forth>2 constant Pos 3 constant Len
- Str ( -- c-addr u ) s" abcdefgh" ;
Str Pos /string drop Len type \ cde Str Pos /string type \ cdefgh Str 1- type \ abcdefg Str char d scan drop Len type \ def Str s" de" search 2drop Len type \ def</lang>
Fortran
<lang fortran>program test_substring
character (*), parameter :: string = 'The quick brown fox jumps over the lazy dog.' character (*), parameter :: substring = 'brown' character , parameter :: c = 'q' integer , parameter :: n = 5 integer , parameter :: m = 15 integer :: i
! Display the substring starting from n characters in and of length m.
write (*, '(a)') string (n : n + m - 1)
! Display the substring starting from n characters in, up to the end of the string.
write (*, '(a)') string (n :)
! Display the whole string minus the last character.
i = len (string) - 1 write (*, '(a)') string (: i)
! Display the substring starting from a known character and of length m.
i = index (string, c) write (*, '(a)') string (i : i + m - 1)
! Display the substring starting from a known substring and of length m.
i = index (string, substring) write (*, '(a)') string (i : i + m - 1)
end program test_substring</lang>
- Output:
quick brown fox quick brown fox jumps over the lazy dog. The quick brown fox jumps over the lazy dog quick brown fox brown fox jumps
Note that in Fortran positions inside character strings are one-based, i. e. the first character is in position one.
Free Pascal
<lang pascal>s[n..n+m] s[n..high(nativeUInt)] s[1..length(s)-1] s[pos(c, s)..pos(c, s)+m] s[pos(p, s)..pos(p, s)+m]</lang>
FreeBASIC
<lang freebasic>' FB 1.05.0 Win64
Dim s As String = "123456789" Dim As Integer n = 3, m = 4 Print Mid(s, n, m) Print Mid(s, n) Print Left(s, Len(s) - 1) 'start from "5" say Print Mid(s, Instr(s, "5"), m) ' start from "12" say Print Mid(s, Instr(s, "12"), m) Sleep</lang>
- Output:
3456 3456789 12345678 5678 1234
Frink
Although Frink runs on a Java Virtual Machine (JVM), its string operations like substr
or indexOf
do not have the broken behavior of Java on high Unicode characters. These return correct values for all Unicode codepoints.
String indices are zero-based.
<lang frink>test = "abcdefg" n = 3 m = 2 println[substrLen[test, n, m]] println[right[test, -m]] println[left[test, -1]] pos = indexOf["c"] if pos != -1
println[substrLen[test, pos, m]]
pos = indexOf[test, "cd"] if pos != -1
println[substrLen[test, pos, m]]
</lang>
Gambas
Click this link to run this code <lang gambas>Public Sub Main() Dim sString As String = "THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG"
Print Mid(sString, 11, 5) 'Starting from n characters in and of m length Print Mid(sString, 17) 'Starting from n characters in, up to the end of the string Print Left(sString, -1) 'Whole string minus last character Print Mid(sString, InStr(sString, "B"), 9) 'Starting from a known character within the string and of m length Print Mid(sString, InStr(sString, "OVER"), 8) 'Starting from a known substring within the string and of m length
End</lang> Output:
BROWN FOX JUMPS OVER THE LAZY DOG THE QUICK BROWN FOX JUMPS OVER THE LAZY DO BROWN FOX OVER THE
GAP
<lang gap>LETTERS;
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
LETTERS{[5 .. 10]};
- "EFGHIJ"</lang>
Go
ASCII
The task originally had no mention of unicode. This solution works with ASCII data. <lang go>package main
import (
"fmt" "strings"
)
func main() {
s := "ABCDEFGH" n, m := 2, 3 // for reference fmt.Println("Index: ", "01234567") fmt.Println("String:", s) // starting from n characters in and of m length fmt.Printf("Start %d, length %d: %s\n", n, m, s[n : n+m]) // starting from n characters in, up to the end of the string fmt.Printf("Start %d, to end: %s\n", n, s[n:]) // whole string minus last character fmt.Printf("All but last: %s\n", s[:len(s)-1]) // starting from a known character within the string and of m length dx := strings.IndexByte(s, 'D') fmt.Printf("Start 'D', length %d: %s\n", m, s[dx : dx+m]) // starting from a known substring within the string and of m length sx := strings.Index(s, "DE") fmt.Printf(`Start "DE", length %d: %s`+"\n", m, s[sx : sx+m])
}</lang>
- Output:
Index: 01234567 String: ABCDEFGH Start 2, length 3: CDE Start 2, to end: CDEFGH All but last: ABCDEFG Start 'D', length 3: DEF Start "DE", length 3: DEF
UTF-8
Strings are generally handled as UTF-8 in Go. <lang go>package main
import (
"fmt" "strings"
)
func main() {
s := "αβγδεζηθ" r := []rune(s) n, m := 2, 3 kc := 'δ' // known character ks := "δε" // known string // for reference fmt.Println("Index: ", "01234567") fmt.Println("String:", s) // starting from n characters in and of m length fmt.Printf("Start %d, length %d: %s\n", n, m, string(r[n:n+m])) // starting from n characters in, up to the end of the string fmt.Printf("Start %d, to end: %s\n", n, string(r[n:])) // whole string minus last character fmt.Printf("All but last: %s\n", string(r[:len(r)-1])) // starting from a known character within the string and of m length dx := strings.IndexRune(s, kc) fmt.Printf("Start %q, length %d: %s\n", kc, m, string([]rune(s[dx:])[:m])) // starting from a known substring within the string and of m length sx := strings.Index(s, ks) fmt.Printf("Start %q, length %d: %s\n", ks, m, string([]rune(s[sx:])[:m]))
}</lang>
- Output:
Index: 01234567 String: αβγδεζηθ Start 2, length 3: γδε Start 2, to end: γδεζηθ All but last: αβγδεζη Start 'δ', length 3: δεζ Start "δε", length 3: δεζ
Groovy
Strings in Groovy are 0-indexed. <lang groovy>def str = 'abcdefgh' def n = 2 def m = 3 // #1 println str[n..n+m-1] /* or */ println str[n..<(n+m)] // #2 println str[n..-1] // #3 println str[0..-2] // #4 def index1 = str.indexOf('d') println str[index1..index1+m-1] /* or */ println str[index1..<(index1+m)] // #5 def index2 = str.indexOf('de') println str[index2..index2+m-1] /* or */ println str[index2..<(index2+m)]</lang>
Haskell
Strings
A string in Haskell is a list of chars: [Char]
- The first three tasks are simply:
*Main> take 3 $ drop 2 "1234567890" "345" *Main> drop 2 "1234567890" "34567890" *Main> init "1234567890" "123456789"
- The last two can be formulated with the following function:
<lang Haskell>t45 n c s | null sub = []
| otherwise = take n. head $ sub where sub = filter(isPrefixOf c) $ tails s</lang>
*Main> t45 3 "4" "1234567890" "456" *Main> t45 3 "45" "1234567890" "456" *Main> t45 3 "31" "1234567890" ""
Data.Text
Testing with an extended set of characters, and using Data.Text functions, including breakOn:
<lang haskell>{-# LANGUAGE OverloadedStrings #-}
import qualified Data.Text as T (Text, take, drop, init, breakOn) import qualified Data.Text.IO as O (putStrLn)
fromMforN :: Int -> Int -> T.Text -> T.Text fromMforN n m s = T.take m (T.drop n s)
fromNtoEnd :: Int -> T.Text -> T.Text fromNtoEnd = T.drop
allButLast :: T.Text -> T.Text allButLast = T.init
fromCharForN, fromStringForN :: Int -> T.Text -> T.Text -> T.Text fromCharForN m needle haystack = T.take m $ snd $ T.breakOn needle haystack
fromStringForN = fromCharForN
-- TEST --------------------------------------------------- main :: IO () main =
mapM_ O.putStrLn ([ fromMforN 9 10 , fromNtoEnd 20 , allButLast , fromCharForN 6 "话" , fromStringForN 6 "大势" ] <*> ["天地不仁仁者人也🐒话说天下大势分久必合🍑合久必分🔥"])</lang>
- Output:
话说天下大势分久必合 合久必分🔥 天地不仁仁者人也🐒话说天下大势分久必合🍑合久必分 话说天下大势 大势分久必合
HicEst
<lang hicest>CHARACTER :: string = 'ABCDEFGHIJK', known = 'B', substring = 'CDE' REAL, PARAMETER :: n = 5, m = 8
WRITE(Messagebox) string(n : n + m - 1), "| substring starting from n, length m" WRITE(Messagebox) string(n :), "| substring starting from n, to end of string" WRITE(Messagebox) string(1: LEN(string)-1), "| whole string minus last character"
pos_known = INDEX(string, known) WRITE(Messagebox) string(pos_known : pos_known+m-1), "| substring starting from pos_known, length m"
pos_substring = INDEX(string, substring) WRITE(Messagebox) string(pos_substring : pos_substring+m-1), "| substring starting from pos_substring, length m"</lang>
Icon and Unicon
<lang Icon>procedure main(arglist) write("Usage: substring <string> <first position> <second position> <single character> <substring>") s := \arglist[1] | "aardvarks" n := \arglist[2] | 5 m := \arglist[3] | 4 c := \arglist[4] | "d" ss := \arglist[5] | "ard"
write( s[n+:m] ) write( s[n:0] ) write( s[1:-1] ) write( s[find(c,s)+:m] ) write( s[find(ss,s)+:m] ) end</lang>
J
<lang J> 5{.3}.'Marshmallow' shmal
3}.'Marshmallow'
shmallow
}.'Marshmallow'
arshmallow
}:'Marshmallow'
Marshmallo
5{.(}.~ i.&'m')'Marshmallow'
mallo
5{.(}.~ I.@E.~&'sh')'Marshmallow'
shmal</lang>
Note that there are other, sometimes better, ways of accomplishing this task.
<lang J> 'Marshmallow'{~(+i.)/3 5 shmal</lang>
The taketo
/ takeafter
and dropto
/ dropafter
utilities from the strings
script further simplify these types of tasks.
<lang J> require 'strings'
'sh' dropto 'Marshmallow'
shmallow
5{. 'sh' dropto 'Marshmallow'
shmal
'sh' takeafter 'Marshmallow'
mallow</lang>
Note also that these operations work the same way on lists of numbers that they do on this example list of characters.
<lang J> 3}. 2 3 5 7 11 13 17 19 7 11 13 17 19
7 11 dropafter 2 3 5 7 11 13 17 19
2 3 5 7 11</lang>
Java
These examples do not work on any valid Unicode code point. The substring functions and functions that take an index may find themselves in the middle of a surrogate pair, returning an invalid result. According to the Java documentation, "A String represents a string in the UTF-16 format in which supplementary characters are represented by surrogate pairs (see the section Unicode Character Representations in the Character class for more information). Index values refer to char code units, so a supplementary character uses two positions in a String." This is also not a complete compilable Java program.
Strings in Java are 0-indexed. <lang java>String x = "testing123"; System.out.println(x.substring(n, n + m)); System.out.println(x.substring(n)); System.out.println(x.substring(0, x.length() - 1)); int index1 = x.indexOf('i'); System.out.println(x.substring(index1, index1 + m)); int index2 = x.indexOf("ing"); System.out.println(x.substring(index2, index2 + m)); //indexOf methods also have an optional "from index" argument which will //make indexOf ignore characters before that index</lang>
JavaScript
The String
object has two similar methods: substr
and substring
.
substr(start, [len])
returns a substring beginning at a specified location and having a specified length.substring(start, [end])
returns a string containing the substring fromstart
up to, but not including,end
.
<lang javascript>var str = "abcdefgh";
var n = 2; var m = 3;
// * starting from n characters in and of m length; str.substr(n, m); // => "cde"
// * starting from n characters in, up to the end of the string; str.substr(n); // => "cdefgh" str.substring(n); // => "cdefgh"
// * whole string minus last character; str.substring(0, str.length - 1); // => "abcdefg"
// * starting from a known character within the string and of m length; str.substr(str.indexOf('b'), m); // => "bcd"
// * starting from a known substring within the string and of m length. str.substr(str.indexOf('bc'), m); // => "bcd"</lang>
Or, in terms of some familiar functional primitives, translating broadly from Haskell:
<lang AppleScript>(function () {
'use strict';
// take :: Int -> Text -> Text function take(n, s) { return s.substr(0, n); }
// drop :: Int -> Text -> Text function drop(n, s) { return s.substr(n); }
// init :: Text -> Text function init(s) { var n = s.length; return (n > 0 ? s.substr(0, n - 1) : undefined); } // breakOn :: Text -> Text -> (Text, Text) function breakOn(strPattern, s) { var i = s.indexOf(strPattern); return i === -1 ? [strPattern, ] : [s.substr(0, i), s.substr(i)]; }
var str = '一二三四五六七八九十';
return JSON.stringify({ 'from n in, of m length': (function (n, m) { return take(m, drop(n, str)); })(4, 3), 'from n in, up to end' :(function (n) { return drop(n, str); })(3), 'all but last' : init(str), 'from matching char, of m length' : (function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('五', str, 3), 'from matching string, of m length':(function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('六七', str, 4) }, null, 2);
})();</lang>
- Output:
<lang JavaScript>{
"from n in, of m length": "五六七", "from n in, up to end": "四五六七八九十", "all but last": "一二三四五六七八九", "from matching char, of m length": "五六七", "from matching string, of m length": "六七八九"
}</lang>
jq
For this exercise we use the Chinese characters for 1 to 10, the character for "10" being "十": <lang jq>def s: "一二三四五六七八九十";</lang>
jq strings are UTF-8 strings, and array-based string indexing and most string functions, such as length/0, are based on Unicode code points. However, the function index/1 currently uses character counts when its input is a string, and therefore in the following we use ix/1 defined as follows: <lang jq>def ix(s): explode | index(s|explode);</lang>
(Users who have access to the regex function match/1 can use it, as illustrated in the comments below.)
Since jq arrays and strings have an index origin of 0, "n characters in" is interpreted to require an index of (n+1). <lang jq># starting from n characters in and of m length: .[n+1: n+m+1] "s[1:2] => \( s[1:2] )",
- starting from n characters in, up to the end of the string: .[n+1:]
"s[9:] => \( s[9:] )",
- whole string minus last character: .[0:length-1]
"s|.[0:length-1] => \(s | .[0:length-1] )",
- starting from a known character within the string and of m length:
# jq 1.4: ix(c) as $i | .[ $i: $i + m] # jq>1.4: match(c).offset as $i | .[ $i: $i + m]
"s | ix(\"五\") as $i | .[$i: $i + 1] => \(s | ix("五") as $i | .[$i: $i + 1] )",
- starting from a known substring within the string and of m length:
# jq 1.4: ix(sub) as $i | .[ $i: $i + m] # jq>1.4: match(sub).offset as $i | .[ $i: $i + m]
"s | ix(\"五六\") as $i | .[$i: $i + 2] => " +
"\( s | ix("五六") as $i | .[$i: $i + 2] )"</lang>
- Output:
<lang sh>$ jq -M -n -r -f Substring.jq s[1:2] => 二 s[9:] => 十 s|.[0:length-1] => 一二三四五六七八九 s | ix("五") as $i | .[$i: $i + 1] => 五 s | ix("五六") as $i | .[$i: $i + 2] => 五六</lang>
Jsish
<lang javascript>#!/usr/local/bin/jsish -u %s
var str = "abcdefgh";
var n = 2; var m = 3;
// In jsish, semi-colon first character lines are echoed with result
- str;
- n;
- m;
// * starting from n characters in and of m length;
- str.substr(n, m);
// * starting from n characters in, up to the end of the string;
- str.substr(n);
- str.substring(n);
// * whole string minus last character;
- str.substring(0, str.length - 1);
// * starting from a known character within the string and of m length;
- str.substr(str.indexOf('b'), m);
// * starting from a known substring within the string and of m length.
- str.substr(str.indexOf('bc'), m);
/* Functional */
var res = (function () {
'use strict'; // take :: Int -> Text -> Text function take(n, s) { return s.substr(0, n); } // drop :: Int -> Text -> Text function drop(n, s) { return s.substr(n); } // init :: Text -> Text function init(s) { var n = s.length; return (n > 0 ? s.substr(0, n - 1) : undefined); } // breakOn :: Text -> Text -> (Text, Text) function breakOn(strPattern, s) { var i = s.indexOf(strPattern); return i === -1 ? [strPattern, ] : [s.substr(0, i), s.substr(i)]; } var str = 'abcdefgh'; return JSON.stringify({ 'from 4 in, of 3 length': (function (n, m) { return take(m, drop(n, str)); })(4, 3), 'from 3 in, up to end' : (function (n) { return drop(n, str); })(3), 'all but last' : init(str), 'from matching b, of length 3' : (function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('b', str, 3),
'from matching bc, of length 4':(function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('bc', str, 4)
}, true);
})();
- res;</lang>
- Output:
prompt$ jsish --U substringing.jsi str ==> abcdefgh n ==> 2 m ==> 3 str.substr(n, m) ==> cde str.substr(n) ==> cdefgh str.substring(n) ==> cdefgh str.substring(0, str.length - 1) ==> abcdefgh str.substr(str.indexOf('b'), m) ==> bcd str.substr(str.indexOf('bc'), m) ==> bcd res ==> { "all but last":"abcdefg", "from 3 in, up to end":"defgh", "from 4 in, of 3 length":"efg", "from matching b, of length 3":"bcd", "from matching bc, of length 4":"bcde" } prompt$ jsish -u -update true substringing.jsi Created substringing.jsi prompt$ jsish -u substringing.jsi [PASS] substringing.jsi
The initial --U is a run with echo mode. The -u -update true puts jsish in unit test mode, and will add a comparison block. After the test pass, the code file is changed to
<lang javascript>#!/usr/local/bin/jsish -u %s
var str = "abcdefgh";
var n = 2; var m = 3;
// In jsish, semi-colon first character lines are echoed with result
- str;
- n;
- m;
// * starting from n characters in and of m length;
- str.substr(n, m);
// * starting from n characters in, up to the end of the string;
- str.substr(n);
- str.substring(n);
// * whole string minus last character;
- str.substring(0, str.length - 1);
// * starting from a known character within the string and of m length;
- str.substr(str.indexOf('b'), m);
// * starting from a known substring within the string and of m length.
- str.substr(str.indexOf('bc'), m);
/* Functional */
var res = (function () {
'use strict'; // take :: Int -> Text -> Text function take(n, s) { return s.substr(0, n); } // drop :: Int -> Text -> Text function drop(n, s) { return s.substr(n); } // init :: Text -> Text function init(s) { var n = s.length; return (n > 0 ? s.substr(0, n - 1) : undefined); } // breakOn :: Text -> Text -> (Text, Text) function breakOn(strPattern, s) { var i = s.indexOf(strPattern); return i === -1 ? [strPattern, ] : [s.substr(0, i), s.substr(i)]; } var str = 'abcdefgh'; return JSON.stringify({ 'from 4 in, of length 3': (function (n, m) { return take(m, drop(n, str)); })(4, 3), 'from 3 in, up to end' : (function (n) { return drop(n, str); })(3), 'all but last' : init(str), 'from matching b, of length 3' : (function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('b', str, 3), 'from matching bc, of length 4':(function (pattern, s, n) { return take(n, breakOn(pattern, s)[1]); })('bc', str, 4)
}, true);
})();
- res;
/*
!EXPECTSTART!
str ==> abcdefgh n ==> 2 m ==> 3 str.substr(n, m) ==> cde str.substr(n) ==> cdefgh str.substring(n) ==> cdefgh str.substring(0, str.length - 1) ==> abcdefgh str.substr(str.indexOf('b'), m) ==> bcd str.substr(str.indexOf('bc'), m) ==> bcd res ==> { "all but last":"abcdefg", "from 3 in, up to end":"defgh", "from 4 in, of length 3":"efg", "from matching b, of length 3":"bcd", "from matching bc, of length 4":"bcde" }
!EXPECTEND!
- /</lang>
Julia
By default, the type of the string is infered from its elements. In the example below, the string s is an ASCII string. In order to interpret the string as an UTF8 string with logical access to its argument, one should use
CharString("/\ʕ•ᴥ•ʔ/\"...)
. Without the CharString declaration, the string is interpreted as an UTF8 string with access through its byte representation.
<lang julia>julia> s = "abcdefg" "abcdefg"
julia> n = 3 3
julia> s[n:end] "cdefg"
julia> m=2 2
julia> s[n:n+m] "cde"
julia> s[1:end-1] "abcdef"
julia> s[search(s,'c')] 'c'
julia> s[search(s,'c'):search(s,'c')+m] "cde"</lang>
Kotlin
Strings in Kotlin are 0-indexed: <lang scala>// version 1.0.6
fun main(args: Array<String>) {
val s = "0123456789" val n = 3 val m = 4 val c = '5' val z = "12" var i: Int println(s.substring(n, n + m)) println(s.substring(n)) println(s.dropLast(1)) i = s.indexOf(c) println(s.substring(i, i + m)) i = s.indexOf(z) println(s.substring(i, i + m))
}</lang>
- Output:
3456 3456789 012345678 5678 1234
LabVIEW
To enhance readability, this task was split into two separate GUI's. In the second, note that "Known Substring" can be a single character.
1:
2:
Lambdatalk
<lang Scheme> {S.slice 1 2 hello brave new world} -> brave new {W.slice 4 11 www.rosetta.org} -> rosetta </lang>
Lang5
<lang lang5>: cr "\n". ; [] '__A set : dip swap __A swap 1 compress append '__A set execute __A
-1 extract nip ; : nip swap drop ; : tuck swap over ; : -rot rot rot ; : 0= 0 == ; : 1+ 1 + ;
- 2dip swap 'dip dip ; : 2drop drop drop ; : |a,b> over - iota + ; : bi* 'dip dip execute ; : bi@ dup bi* ;
- comb "" split ; : concat "" join ; : empty? length 0= ; : tail over lensize |a,b> subscript ;
- lensize length nip ; : while do 'dup dip 'execute 2dip rot if dup 2dip else break then loop 2drop ;
- <substr> comb -rot over + |a,b> subscript concat ;
- str-tail tail concat ;
- str-index
: 2streq 2dup over lensize iota subscript eq '* reduce ; swap 'comb bi@ length -rot 0 -rot "2dup 'lensize bi@ <=" "2streq if 0 reshape else '1+ 2dip 0 extract drop then" while empty? if 2drop tuck == if drop -1 then else 4 ndrop -1 then ;
'abcdefgh 'str set 2 'n set 3 'm set n m str <substr> str comb n str-tail str "d" str-index m str <substr> str "de" str-index m str <substr></lang>
Lasso
<lang Lasso>local(str = 'The quick grey rhino jumped over the lazy green fox.')
//starting from n characters in and of m length;
- str->substring(16,5) //rhino
//starting from n characters in, up to the end of the string
- str->substring(16) //rhino jumped over the lazy green fox.
//whole string minus last character
- str->substring(1,#str->size - 1) //The quick grey rhino jumped over the lazy green fox
//starting from a known character within the string and of m length;
- str->substring(#str->find('g'),10) //grey rhino
//starting from a known substring within the string and of m length
- str->substring(#str->find('rhino'),12) //rhino jumped</lang>
LFE
From the LFE REPL:
<lang lisp> > (set n 3) 3 > (set m 5) 5 > (string:sub_string "abcdefghijklm" n) "cdefghijklm" > (string:sub_string "abcdefghijklm" n (+ n m -1)) "cdefg" > (string:sub_string "abcdefghijklm" 1 (- (length "abcdefghijklm") 1)) "abcdefghijkl" > (set char-index (string:chr "abcdefghijklm" #\e)) 5 > (string:sub_string "abcdefghijklm" char-index (+ char-index m -1)) "efghi" > (set start-str (string:str "abcdefghijklm" "efg")) 5 > (string:sub_string "abcdefghijklm" start-str (+ start-str m -1)) "efghi" </lang>
Liberty BASIC
<lang lb>'These tasks can be completed with various combinations of Liberty Basic's 'built in Mid$()/ Instr()/ Left$()/ Right$()/ and Len() functions, but these 'examples only use the Mid$()/ Instr()/ and Len() functions.
baseString$ = "Thequickbrownfoxjumpsoverthelazydog." n = 12 m = 5
'starting from n characters in and of m length Print Mid$(baseString$, n, m)
'starting from n characters in, up to the end of the string Print Mid$(baseString$, n)
'whole string minus last character Print Mid$(baseString$, 1, (Len(baseString$) - 1))
'starting from a known character within the string and of m length Print Mid$(baseString$, Instr(baseString$, "f", 1), m)
'starting from a known substring within the string and of m length Print Mid$(baseString$, Instr(baseString$, "jump", 1), m)</lang>
Lingo
<lang lingo>str = "The quick brown fox jumps over the lazy dog"
-- starting from n characters in and of m length n = 5 m = 11 put str.char[n..n+m-1] -- "quick brown"
-- starting from n characters in, up to the end of the string n = 11 put str.char[n..str.length] -- "brown fox jumps over the lazy dog"
-- whole string minus last character put str.char[1..str.length-1] -- "The quick brown fox jumps over the lazy do"
-- starting from a known character within the string and of m length c = "x" m = 7 pos = offset(c, str) put str.char[pos..pos+m-1] -- "x jumps"
-- starting from a known substring within the string and of m length sub = "fox" m = 9 pos = offset(sub, str) put str.char[pos..pos+m-1] -- "fox jumps"</lang>
LiveCode
<lang LiveCode>put "pple" into x answer char 2 to char 5 of x // n = 2, m=5 answer char 2 to len(x) of x // n = 2, m = len(x), can also use -1 answer char 1 to -2 of x // n = 1, m = 1 less than length of string answer char offset("p",x) to -1 of x // known char "p" to end of string answer char offset("pl",x) to -1 of x // known "pl" to end of string</lang> n.b. Offset also supports a third parameter "charsToSkip" allowing you to loop through subsequent matches of the substring.
Logo
The following are defined to behave similarly to the built-in index operator ITEM. As with most Logo list operators, these are designed to work for both words (strings) and lists. <lang logo>to items :n :thing
if :n >= count :thing [output :thing] output items :n butlast :thing
end
to butitems :n :thing
if or :n <= 0 empty? :thing [output :thing] output butitems :n-1 butfirst :thing
end
to middle :n :m :thing
output items :m-(:n-1) butitems :n-1 :thing
end
to lastitems :n :thing
if :n >= count :thing [output :thing] output lastitems :n butfirst :thing
end
to starts.with :sub :thing
if empty? :sub [output "true] if empty? :thing [output "false] if not equal? first :sub first :thing [output "false] output starts.with butfirst :sub butfirst :thing
end
to members :sub :thing
output cascade [starts.with :sub ?] [bf ?] :thing
end
- note
- Logo indices start at one
make "s "abcdefgh print items 3 butitems 2 :s ; cde print middle 3 5 :s ; cde print butitems 2 :s ; cdefgh print butlast :s ; abcdefg print items 3 member "d :s ; def print items 3 members "de :s ; def</lang>
Logtalk
Using atoms for representing strings and usng the same sample data as e.g. in the Java solution: <lang logtalk>
- - object(substring).
:- public(test/5).
test(String, N, M, Character, Substring) :- sub_atom(String, N, M, _, Substring1), write(Substring1), nl, sub_atom(String, N, _, 0, Substring2), write(Substring2), nl, sub_atom(String, 0, _, 1, Substring3), write(Substring3), nl, % there can be multiple occurences of the character once(sub_atom(String, Before4, 1, _, Character)), sub_atom(String, Before4, M, _, Substring4), write(Substring4), nl, % there can be multiple occurences of the substring once(sub_atom(String, Before5, _, _, Substring)), sub_atom(String, Before5, M, _, Substring5), write(Substring5), nl.
- - end_object.
</lang>
- Output:
<lang text> | ?- ?- substring::test('abcdefgh', 2, 3, 'b', 'bc'). cde cdefgh abcdefg bcd bcd yes </lang>
Lua
<lang lua>str = "abcdefghijklmnopqrstuvwxyz" n, m = 5, 15
print( string.sub( str, n, m ) ) -- efghijklmno print( string.sub( str, n, -1 ) ) -- efghijklmnopqrstuvwxyz print( string.sub( str, 1, -2 ) ) -- abcdefghijklmnopqrstuvwxy
pos = string.find( str, "i" ) if pos ~= nil then print( string.sub( str, pos, pos+m ) ) end -- ijklmnopqrstuvwx
pos = string.find( str, "ijk" ) if pos ~= nil then print( string.sub( str, pos, pos+m ) ) end-- ijklmnopqrstuvwx
-- Alternative (more modern) notation
print ( str:sub(n,m) ) -- efghijklmno print ( str:sub(n) ) -- efghijklmnopqrstuvwxyz print ( str:sub(1,-2) ) -- abcdefghijklmnopqrstuvwxy
pos = str:find "i" if pos then print (str:sub(pos,pos+m)) end -- ijklmnopqrstuvwx
pos = str:find "ijk" if pos then print (str:sub(pos,pos+m)) end d-- ijklmnopqrstuvwx
</lang>
M2000 Interpreter
By default a sting can contain anything, and has a maximum length of 2GBytes. Literals are always UTF-16LE. Print/edit done as UTF-16LE. But we can use Str$(a_string) to convert UTF-16LE to Ansi, using Locale id. To display it we can use Chr$(a_String), to convert back to UTF-16LE. Mid$, Right$, Left$, Instr,RInstr works for Ansi using "as byte". For Utf16-le, we get next 16bit value, not exactly next char, but for many languages it is exactly next char.
Function for length always return length as Words (two bytes), so we can get half, if we have an odd number of ansi characters. For Utf16-le there is another Len function,Len.Disp which returns the needed positions for displaying characters. So Print LEN.DISP("aããz")=4 : Print Len("̃ãz")=4
<lang M2000 Interpreter> Module CheckAnsi {
\\ ANSI STRING Locale 1033 \\ convert UTF16-LE to ANSI 8bit s$ =Str$("ABCDEFG") Print Len(s$)=3.5 ' 3.5 words, means 7 bytes (3.5*2) AnsiLen=Len(s$)*2 ' From 4th byte get 3 bytes n=4 m=3 substring$=Mid$(s$, n, m as byte) substring2End$=Mid$(s$, n , AnsiLen as byte) substringMinusOne$=Left$(s$, AnsiLen-1 as byte) substringFromKnownCharacter$=Mid$(s$, Instr(s$, str$("B") as byte) , m as byte) substringFromKnownSubstring$=Mid$(s$, Instr(s$, str$("BC") as byte) , m as byte) Print Len(substring$)*2=m \\ convert to UTF-16LE Print Chr$(substring$)="DEF" Print Chr$(substring2End$)="DEFG" Print Chr$(substringMinusOne$)="ABCDEF" Print Chr$(substringFromKnownCharacter$)="BCD" Print Chr$(substringFromKnownSubstring$)="BCD"
} CheckAnsi Module CheckUTF16LE {
s$ ="ABCDEFG" Print Len(s$)=7 Utf16Len=Len(s$) ' From 4th byte get 3 bytes n=4 m=3 substring$=Mid$(s$, n, m) substring2End$=Mid$(s$, n , Utf16Len) substringMinusOne$=Left$(s$, Utf16Len-1) substringFromKnownCharacter$=Mid$(s$, Instr(s$, "B") , m) substringFromKnownSubstring$=Mid$(s$, Instr(s$, "BC") , m) Print Len(substring$)=m \\ convert to UTF-16LE Print substring$="DEF" Print substring2End$="DEFG" Print substringMinusOne$="ABCDEF" Print substringFromKnownCharacter$="BCD" Print substringFromKnownSubstring$="BCD"
} CheckUTF16LE
</lang>
Maple
<lang Maple> > n, m := 3, 5: > s := "The Higher, The Fewer!": > s[ n .. n + m - 1 ];
"e Hig"
</lang> There are a few ways to get everything from the n-th character on. <lang Maple> > s[ n .. -1 ] = s[ n .. ];
"e Higher, The Fewer!" = "e Higher, The Fewer!"
> StringTools:-Drop( s, n - 1 );
"e Higher, The Fewer!"
</lang> There are a few ways to get all but the last character. <lang Maple> > s[ 1 .. -2 ] = s[ .. -2 ]; "The Higher, The Fewer" = "The Higher, The Fewer"
> StringTools:-Chop( s );
"The Higher, The Fewer"
</lang>
The searchtext
command returns the position of a matching substring.
<lang Maple>
> pos := searchtext( ",", s ):
> s[ pos .. pos + m - 1 ];
", The"
> pos := searchtext( "Higher", s ): > s[ pos .. pos + m - 1 ];
"Highe"
</lang>
But, note that searchtext
returns 0 when there is no match, and 0 is not a valid index into a string.
Mathematica
The StringTake
and StringDrop
are relevant for this exercise.
<lang Mathematica> n = 2 m = 3 StringTake["Mathematica", {n+1, n+m-1}]
StringDrop["Mathematica", n]
(* StringPosition returns a list of starting and ending character positions for a substring *) pos = StringPosition["Mathematica", "e"]11 StringTake["Mathematica", {pos, pos+m-1}]
(* Similar to above *) pos = StringPosition["Mathematica", "the"]1 StringTake["Mathematica", {pos, pos+m-1}] </lang>
MATLAB / Octave
Unicode, UTF-8, UTF-16 is only partially supported. In some cases, a conversion of unicode2native() or native2unicode() is necessary. <lang Matlab>
% starting from n characters in and of m length; s(n+(1:m)) s(n+1:n+m) % starting from n characters in, up to the end of the string; s(n+1:end) % whole string minus last character; s(1:end-1) % starting from a known character within the string and of m length; s(find(s==c,1)+[0:m-1]) % starting from a known substring within the string and of m length. s(strfind(s,pattern)+[0:m-1])
</lang>
Maxima
<lang maxima>s: "the quick brown fox jumps over the lazy dog"; substring(s, 17); /* "fox jumps over the lazy dog" */ substring(s, 17, 20); /* "fox" */</lang>
MUMPS
MUMPS has the first position in a string numbered as 1. <lang MUMPS> SUBSTR(S,N,M,C,K)
;show substring operations ;S is the string ;N is a position within the string (that is, n<length(string)) ;M is an integer of positions to show ;C is a character within the string S ;K is a substring within the string S ;$Find returns the position after the substring NEW X WRITE !,"The base string is:",!,?5,"'",S,"'" WRITE !,"From position ",N," for ",M," characters:" WRITE !,?5,$EXTRACT(S,N,N+M-1) WRITE !,"From position ",N," to the end of the string:" WRITE !,?5,$EXTRACT(S,N,$LENGTH(S)) WRITE !,"Whole string minus last character:" WRITE !,?5,$EXTRACT(S,1,$LENGTH(S)-1) WRITE !,"Starting from character '",C,"' for ",M," characters:" SET X=$FIND(S,C)-$LENGTH(C) WRITE !,?5,$EXTRACT(S,X,X+M-1) WRITE !,"Starting from string '",K,"' for ",M," characters:" SET X=$FIND(S,K)-$LENGTH(K) W !,?5,$EXTRACT(S,X,X+M-1) QUIT
</lang> Usage:
USER>D SUBSTR^ROSETTA("ABCD1234efgh",3,4,"D","23") The base string is: 'ABCD1234efgh' From position 3 for 4 characters: CD12 From position 3 to the end of the string: CD1234efgh Whole string minus last character: ABCD1234efg Starting from character 'D' for 4 characters: D123 Starting from string '23' for 4 characters: 234e
Nanoquery
<lang Nanoquery>str = "test string"
println substr(str, m, m + n) println substr(str, n, len(str)) println substr(str, 0, len(str) - 1) println substr(str, str.indexOf("s"), str.indexOf("s") + m) println substr(str, str.indexOf("str"), str.indexOf("str") + m)</lang>
Nemerle
<lang Nemerle>using System; using System.Console;
module Substrings {
Main() : void { string s = "0123456789"; def n = 3; def m = 2; def c = '3'; def z = "345";
WriteLine(s.Substring(n, m)); WriteLine(s.Substring(n, s.Length - n)); WriteLine(s.Substring(0, s.Length - 1)); WriteLine(s.Substring(s.IndexOf(c,0,s.Length), m)); WriteLine(s.Substring(s.IndexOf(z, 0, s.Length), m)); }
}</lang>
NetRexx
<lang NetRexx>/* NetRexx */
options replace format comments java crossref savelog symbols
s = 'abcdefghijk' n = 4 m = 3
say s say s.substr(n, m) say s.substr(n) say s.substr(1, s.length - 1) say s.substr(s.pos('def'), m) say s.substr(s.pos('g'), m)
return </lang>
- Output:
abcdefghijk def defghijk abcdefghij def ghi
newLISP
<lang newLISP>> (set 'str "alphabet" 'n 2 'm 4) 4 > ; starting from n characters in and of m length > (slice str n m) "phab" > ; starting from n characters in, up to the end of the string > (slice str n) "phabet" > ; whole string minus last character > (chop str) "alphabe" > ; starting from a known character within the string and of m length > (slice str (find "l" str) m) "lpha" > ; starting from a known substring within the string and of m length > (slice str (find "ph" str) m) "phab" </lang>
Nim
<lang nim>import strutils
let
s = "abcdefgh" n = 2 m = 3 c = 'd' cs = "cd"
var i = 0
- starting from n=2 characters in and m=3 in length
echo s[n-1 .. n+m-2]
- starting from n characters in, up to the end of the string
echo s[n-1 .. s.high]
- whole string minus last character:
echo s[0 .. <s.high]
- starting from a known character c='d'within the string and of m length
i = s.find(c) echo s[i .. <i+m]
- starting from a known substring cs="cd" within the string and of m length
i = s.find(cs) echo s[i .. <i+m]</lang>
Niue
<lang Niue>( based on the JavaScript code ) 'abcdefgh 's ; s str-len 'len ; 2 'n ; 3 'm ;
( starting from n characters in and of m length ) s n n m + substring . ( => cde ) newline
( starting from n characters in, up to the end of the string ) s n len substring . ( => cdefgh ) newline
( whole string minus last character ) s 0 len 1 - substring . ( => abcdefg ) newline
( starting from a known character within the string and of m length ) s s 'b str-find dup m + substring . ( => bcd ) newline
( starting from a known substring within the string and of m length ) s s 'bc str-find dup m + substring . ( => bcd ) newline </lang>
Objeck
<lang objeck> bundle Default {
class SubString { function : Main(args : String[]) ~ Nil { s := "0123456789";
n := 3; m := 4; c := '2'; sub := "456";
s->SubString(n, m)->PrintLine(); s->SubString(n)->PrintLine(); s->SubString(0, s->Size())->PrintLine(); s->SubString(s->Find(c), m)->PrintLine(); s->SubString(s->Find(sub), m)->PrintLine(); } }
} </lang>
OCaml
<lang ocaml># let s = "ABCDEFGH" ;; val s : string = "ABCDEFGH"
- let n, m = 2, 3 ;;
val n : int = 2 val m : int = 3
- String.sub s n m ;;
- : string = "CDE"
- String.sub s n (String.length s - n) ;;
- : string = "CDEFGH"
- String.sub s 0 (String.length s - 1) ;;
- : string = "ABCDEFG"
- String.sub s (String.index s 'D') m ;;
- : string = "DEF"
- #load "str.cma";;
- let n = Str.search_forward (Str.regexp_string "DE") s 0 in
String.sub s n m ;;
- : string = "DEF"</lang>
Oforth
<lang Oforth>: substrings(s, n, m)
s sub(n, m) println s right(s size n - 1 +) println s left(s size 1 - ) println s sub(s indexOf('d'), m) println s sub(s indexOfAll("de"), m) println ;</lang>
- Output:
"abcdefgh" 2 3 substrings bcd bcdefgh abcdefg def def
Oz
<lang oz>declare
fun {DropUntil Xs Prefix} case Xs of nil then nil [] _|Xr then if {List.isPrefix Prefix Xs} then Xs else {DropUntil Xr Prefix} end end end
Digits = "1234567890"
in
{ForAll [{List.take {List.drop Digits 2} 3} = "345" {List.drop Digits 2} = "34567890" {List.take Digits {Length Digits}-1} = "123456789" {List.take {DropUntil Digits "4"} 3} = "456" {List.take {DropUntil Digits "56"} 3} = "567" {List.take {DropUntil Digits "31"} 3} = "" ] System.showInfo}</lang>
PARI/GP
<lang parigp> \\ Returns the substring of string str specified by the start position s and length n. \\ If n=0 then to the end of str. \\ ssubstr() 3/5/16 aev ssubstr(str,s=1,n=0)={ my(vt=Vecsmall(str),ve,vr,vtn=#str,n1); if(vtn==0,return("")); if(s<1||s>vtn,return(str)); n1=vtn-s+1; if(n==0,n=n1); if(n>n1,n=n1); ve=vector(n,z,z-1+s); vr=vecextract(vt,ve); return(Strchr(vr)); }
{\\ TEST my(s="ABCDEFG",ns=#s); print(" *** Testing ssubstr():"); print("1.",ssubstr(s,2,3)); print("2.",ssubstr(s)); print("3.",ssubstr(s,,ns-1)); print("4.",ssubstr(s,2)); print("5.",ssubstr(s,,4)); print("6.",ssubstr(s,0,4)); print("7.",ssubstr(s,3,7)); print("8.|",ssubstr("",1,4),"|"); } </lang>
- Output:
*** Testing ssubstr(): 1.BCD 2.ABCDEFG 3.ABCDEF 4.BCDEFG 5.ABCD 6.ABCDEFG 7.CDEFG 8.||
Pascal
See Delphi and Free Pascal
Perl
<lang perl>my $str = 'abcdefgh'; print substr($str, 2, 3), "\n"; # Returns 'cde' print substr($str, 2), "\n"; # Returns 'cdefgh' print substr($str, 0, -1), "\n"; #Returns 'abcdefg' print substr($str, index($str, 'd'), 3), "\n"; # Returns 'def' print substr($str, index($str, 'de'), 3), "\n"; # Returns 'def'</lang>
Phix
<lang Phix>--(1) starting from n characters in and of m length; --(2) starting from n characters in, up to the end of the string; --(3) whole string minus last character; --(4) starting from a known character within the string and of m length; --(5) starting from a known substring within the string and of m length.
constant sentence = "the last thing the man said was the",
n = 10, m = 5
integer k, l l = n+m-1 if l<=length(sentence) then
?sentence[n..l] -- (1)
end if if n<=length(sentence) then
?sentence[n..-1] -- (2) or [n..$]
end if if length(sentence)>0 then
?sentence[1..-2] -- (3) or [1..$-1]
end if k = find('m',sentence) l = k+m-1 if l<=length(sentence) then
?sentence[k..l] -- (4)
end if k = match("aid",sentence) l = k+m-1 if l<=length(sentence) then
?sentence[k..l] -- (5)
end if</lang>
- Output:
"thing" "thing the man said was the" "the last thing the man said was th" "man s" "aid w"
Alternative version with no error handling, for those in a hurry (same ouput): <lang Phix>?sentence[n..n+m-1] ?sentence[n..-1] ?sentence[1..-2] ?(sentence[find('m',sentence)..$])[1..m] ?(sentence[match("aid",sentence)..$])[1..m]</lang>
PHP
<lang php><?php $str = 'abcdefgh'; $n = 2; $m = 3; echo substr($str, $n, $m), "\n"; //cde echo substr($str, $n), "\n"; //cdefgh echo substr($str, 0, -1), "\n"; //abcdefg echo substr($str, strpos($str, 'd'), $m), "\n"; //def echo substr($str, strpos($str, 'de'), $m), "\n"; //def ?></lang>
PicoLisp
<lang PicoLisp>(let Str (chop "This is a string")
(prinl (head 4 (nth Str 6))) # From 6 of 4 length (prinl (nth Str 6)) # From 6 up to the end (prinl (head -1 Str)) # Minus last character (prinl (head 8 (member "s" Str))) # From character "s" of length 8 (prinl # From "isa" of length 8 (head 8 (seek '((S) (pre? "is a" S)) Str) ) ) )</lang>
- Output:
is a is a string This is a strin s is a s is a str
PL/I
<lang PL/I> s='abcdefghijk'; n=4; m=3; u=substr(s,n,m); u=substr(s,n); u=substr(s,1,length(s)-1); u=left(s,length(s)-1); u=substr(s,1,length(s)-1); u=substr(s,index(s,'g'),m); </lang>
PowerShell
Since .NET and PowerShell use zero-based indexing, all character indexes have to be reduced by one. <lang powershell># test string $s = "abcdefgh"
- test parameters
$n, $m, $c, $s2 = 2, 3, [char]'d', $s2 = 'cd'
- starting from n characters in and of m length
- n = 2, m = 3
$s.Substring($n-1, $m) # returns 'bcd'
- starting from n characters in, up to the end of the string
- n = 2
$s.Substring($n-1) # returns 'bcdefgh'
- whole string minus last character
$s.Substring(0, $s.Length - 1) # returns 'abcdefg'
- starting from a known character within the string and of m length
- c = 'd', m =3
$s.Substring($s.IndexOf($c), $m) # returns 'def'
- starting from a known substring within the string and of m length
- s2 = 'cd', m = 3
$s.Substring($s.IndexOf($s2), $m) # returns 'cde'</lang>
Prolog
<lang prolog> substring_task(Str, N, M, Char, SubStr) :-
sub_string(Str, N, M, _, Span), sub_string(Str, N, _, 0, ToEnd), sub_string(Str, 0, _, 1, MinusLast), string_from_substring_to_m(Str, Char, M, FromCharToMth), string_from_substring_to_m(Str, SubStr, M, FromSubToM), maplist( writeln, [ 'from n to m ':Span, 'from n to end ': ToEnd, 'string minus last char ': MinusLast, 'form known char to m ': FromCharToMth, 'from known substring to m ': FromSubToM ]).
string_from_substring_to_m(String, Sub, M, FromSubToM) :-
sub_string(String, Before, _, _, Sub), sub_string(String, Before, M, _, FromSubToM).
</lang>
Running it:
<lang prolog> ?- substring_task("abcdefghijk", 2, 4, "d", "ef"). from n to m :cdef from n to end :cdefghijk string minus last char :abcdefghij form known char to m :defg from known substring to m :efgh true </lang>
PureBasic
<lang PureBasic>If OpenConsole()
Define baseString.s, m, n baseString = "Thequickbrownfoxjumpsoverthelazydog." n = 12 m = 5 ;Display the substring starting from n characters in and of m length. PrintN(Mid(baseString, n, m)) ;Display the substring starting from n characters in, up to the end of the string. PrintN(Mid(baseString, n)) ;or PrintN(Right(baseString, Len(baseString) - n)) ;Display the substring whole string minus last character PrintN(Left(baseString, Len(baseString) - 1)) ;Display the substring starting from a known character within the string and of m length. PrintN(Mid(baseString, FindString(baseString, "b", 1), m))
;Display the substring starting from a known substring within the string and of m length. PrintN(Mid(baseString, FindString(baseString, "ju", 1), m))
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit") Input() CloseConsole()
EndIf</lang>
- Output:
wnfox wnfoxjumpsoverthelazydog. Thequickbrownfoxjumpsoverthelazydog brown jumps
Python
Python uses zero-based indexing, so the n'th character is at index n-1.
<lang python>>>> s = 'abcdefgh' >>> n, m, char, chars = 2, 3, 'd', 'cd' >>> # starting from n=2 characters in and m=3 in length; >>> s[n-1:n+m-1] 'bcd' >>> # starting from n characters in, up to the end of the string; >>> s[n-1:] 'bcdefgh' >>> # whole string minus last character; >>> s[:-1] 'abcdefg' >>> # starting from a known character char="d" within the string and of m length; >>> indx = s.index(char) >>> s[indx:indx+m] 'def' >>> # starting from a known substring chars="cd" within the string and of m length. >>> indx = s.index(chars) >>> s[indx:indx+m] 'cde' >>></lang>
R
<lang R>s <- "abcdefgh" n <- 2; m <- 2; char <- 'd'; chars <- 'cd' substring(s, n, n + m) substring(s, n) substring(s, 1, nchar(s)-1) indx <- which(strsplit(s, )1 %in% strsplit(char, )1) substring(s, indx, indx + m) indx <- which(strsplit(s, )1 %in% strsplit(chars, )1)[1] substring(s, indx, indx + m)</lang>
Racket
<lang Racket>
- lang racket
(define str "abcdefghijklmnopqrstuvwxyz")
(define n 10) (define m 2) (define start-char #\x) (define start-str "xy")
- starting from n characters in and of m length;
(substring str n (+ n m)) ; -> "kl"
- starting from n characters in, up to the end of the string;
(substring str m) ; -> "klmnopqrstuvwxyz"
- whole string minus last character;
(substring str 0 (sub1 (string-length str))) ; -> "abcdefghijklmnopqrstuvwxy"
- starting from a known character within the string and of m length;
(substring str (caar (regexp-match-positions (regexp-quote (string start-char))
str))) ; -> "xyz"
- starting from a known substring within the string and of m length.
(substring str (caar (regexp-match-positions (regexp-quote start-str)
str))) ; -> "xyz"
</lang>
Raku
(formerly Perl 6) <lang perl6>my $str = 'abcdefgh'; my $n = 2; my $m = 3; say $str.substr($n, $m); say $str.substr($n); say $str.substr(0, *-1); say $str.substr($str.index('d'), $m); say $str.substr($str.index('de'), $m);</lang>
Raven
<lang Raven>define println use $s
$s print "\n" print
"0123456789" as $str
$str 3 2 extract println # at 4th pos get 2 chars $str 8 4 extract println # at 9th pos get 4 chars (when only 1 char available)
$str 3 $str length extract println # at 4th pos get all chars to end of str
$str 3 0x7FFFFFFF extract println # at 4th pos get all chars to end of str
$str 3 -1 extract println # at 4th pos get rest of chars but last one $str 0 -1 extract println # all chars but last one
"3" as $matchChr # starting chr for extraction 4 as $subLen # Nr chars after found starting char $str $matchChr split as $l "" $l 0 set $l $matchChr join 0 $subLen extract println
"345" as $matchChrs # starting chrs for extraction 6 as $subLen # Nr chars after found starting chars $str $matchChrs split as $l "" $l 0 set $l $matchChrs join 0 $subLen extract println</lang>
- Output:
34 89 3456789 3456789 345678 012345678 3456 345678
REBOL
<lang REBOL>REBOL [ Title: "Retrieve Substring" URL: http://rosettacode.org/wiki/Substring#REBOL ]
s: "abcdefgh" n: 2 m: 3 char: #"d" chars: "cd"
- Note that REBOL uses base-1 indexing. Strings are series values,
- just like blocks or lists so I can use the same words to manipulate
- them. All these examples use the 'copy' function against the 's'
- string with a particular offset as needed.
- For the fragment "copy/part skip s n - 1 m", read from right to
- left. First you have 'm', which we ignore for now. Then evaluate
- 'n - 1' (makes 1), to adjust the offset. Then 'skip' jumps from the
- start of the string by that offset. 'copy' starts copying from the
- new start position and the '/part' refinement limits the copy by 'm'
- characters.
print ["Starting from n, length m:" copy/part skip s n - 1 m]
- It may be helpful to see the expression with optional parenthesis
print ["Starting from n, length m (parens):" (copy/part (skip s (n - 1)) m)]
- This example is much simpler, so hopefully it's easier to see how
- the string start is position for the copy
print ["Starting from n to end of string:" copy skip s n - 1]
print ["Whole string minus last character:" copy/part s (length? s) - 1]
print ["Starting from known character, length m:" copy/part find s char m]
print ["Starting from substring, length m:" copy/part find s chars m]</lang>
- Output:
Script: "Retrieve Substring" (6-Dec-2009) Starting from n, length m: bcd Starting from n, length m (parens): bcd Starting from n to end of string: bcdefgh Whole string minus last character: abcdefg Starting from known character, length m: def Starting from substring, length m: cde
REXX
Note: in REXX, the 1st character index of a string is 1, not 0. <lang rexx>/*REXX program demonstrates various ways to extract substrings from a string of characters.*/ $='abcdefghijk'; n=4; m=3 /*define some constants: string, index, length of string. */ say 'original string='$ /* [↑] M can be zero (which indicates a null string).*/ L=length($) /*the length of the $ string (in bytes or characters).*/
say center(1,30,'═') /*show a centered title for the 1st task requirement. */
u=substr($, n, m) /*start from N characters in and of M length. */ say u parse var $ =(n) a +(m) /*an alternate method by using the PARSE instruction. */ say a
say center(2,30,'═') /*show a centered title for the 2nd task requirement. */
u=substr($,n) /*start from N characters in, up to the end-of-string. */ say u parse var $ =(n) a /*an alternate method by using the PARSE instruction. */ say a
say center(3,30,'═') /*show a centered title for the 3rd task requirement. */
u=substr($, 1, L-1) /*OK: the entire string except the last character. */ say u v=substr($, 1, max(0, L-1) ) /*better: this version handles the case of a null string. */ say v lm=L-1 parse var $ a +(lm) /*an alternate method by using the PARSE instruction. */ say a
say center(4,30,'═') /*show a centered title for the 4th task requirement. */
u=substr($,pos('g',$), m) /*start from a known char within the string of length M. */ say u parse var $ 'g' a +(m) /*an alternate method by using the PARSE instruction. */ say a
say center(5,30,'═') /*show a centered title for the 5th task requirement. */
u=substr($,pos('def',$),m) /*start from a known substr within the string of length M.*/ say u parse var $ 'def' a +(m) /*an alternate method by using the PARSE instruction. */ say a /*stick a fork in it, we're all done and Bob's your uncle.*/</lang> output when using the (internal) default strings:
original string=abcdefghijk ══════════════1═══════════════ def def ══════════════2═══════════════ defghijk defghijk ══════════════3═══════════════ abcdefghij abcdefghij abcdefghij ══════════════4═══════════════ ghi ghi ══════════════5═══════════════ def def
Programming note: generally, the REXX parse statement is faster than using an assignment statement and using a BIF (built-in function), but the use of parse is more obtuse to novice programmers.
Ring
<lang ring>cStr = "a":"h" # 'abcdefgh' n = 3 m = 3
- starting from n characters in and of m length
See substr(cStr,n, m) + nl #=> cde
- starting from n characters in, up to the end of the string
See substr(cStr,n) + nl #=> cdefgh
- whole string minus last character
See substr(cstr,1,len(cStr)-1) + nl #=> abcdefg
- starting from a known character within the string and of m length
See substr(cStr,substr(cStr,"e"),m) +nl #=> efg
- starting from a known substring within the string and of m length
See substr(cStr,substr(cStr,"de"),m) +nl #=> def </lang>
RPG
<lang rpg> * 1...5....1....5....2....5..
D myString S 30 inz('Liebe bewegt das Universum!') D output S 30 inz() D n S 2 0 inz(1) D m S 2 0 inz(5) D length S 2 0 inz(0) D find S 2 0 inz(0) /free *inlr = *on; dsply %subst(myString:n:m); dsply %subst(myString:7:20); length = %len(%trim(myString)); dsply %subst(myString:1:length-1); find = %scan('U':myString); dsply %subst(myString:find:9); find = %scan('bewegt':myString); dsply %subst(myString:find:%len('bewegt')); output = ' *** end *** '; dsply ' ' ' ' output; /end-free</lang>
- Output:
DSPLY Liebe DSPLY bewegt das Universum DSPLY Liebe bewegt das Universum DSPLY Universum DSPLY bewegt
Ruby
<lang ruby>str = 'abcdefgh' n = 2 m = 3 puts str[n, m] #=> cde puts str[n..m] #=> cd puts str[n..-1] #=> cdefgh puts str[0..-2] #=> abcdefg puts str[str.index('d'), m] #=> def puts str[str.index('de'), m] #=> def puts str[/a.*d/] #=> abcd</lang>
Run BASIC
<lang runbasic>n = 2 m = 3 s$ = "abcd" a$ = mid$(a$,n,m) ' starting from n characters in and of m length a$ = mid$(a$,n) ' starting from n characters in, up to the end of the string a$ = Print mid$(a$,1,(len(a$)-1)) ' whole string minus last character a$ = mid$(a$,instr(a$,s$,1),m) ' starting from a known character within the string and of m length a$ = mid$(a$,instr(a$,s$,1), m) ' starting from a known substring within the string and of m length.</lang>
Rust
<lang rust> let s = "abc文字化けdef"; let n = 2; let m = 3;
// Print 3 characters starting at index 2 (c文字)
println!("{}", s.chars().skip(n).take(m).collect::<String>());
// Print all characters starting at index 2 (c文字化けdef)
println!("{}", s.chars().skip(n).collect::<String>());
// Print all characters except the last (abc文字化けde)
println!("{}", s.chars().rev().skip(1).collect::<String>());
// Print 3 characters starting with 'b' (bc文)
let cpos = s.find('b').unwrap(); println!("{}", s[cpos..].chars().take(m).collect::<String>());
// Print 3 characters starting with "けd" (けde)
let spos = s.find("けd").unwrap(); println!("{}", s[spos..].chars().take(m).collect::<String>()); </lang>
SAS
<lang sas>data _null_;
a="abracadabra"; b=substr(a,2,3); /* first number is position, starting at 1, second number is length */ put _all_;
run;</lang>
Sather
<lang sather>class MAIN is
main is s ::= "hello world shortest program"; #OUT + s.substring(12, 5) + "\n"; #OUT + s.substring(6) + "\n"; #OUT + s.head( s.size - 1) + "\n"; #OUT + s.substring(s.search('w'), 5) + "\n"; #OUT + s.substring(s.search("ro"), 3) + "\n"; end;
end;</lang>
Scala
<lang scala>object Substring {
// Ruler 1 2 3 4 5 6 // 012345678901234567890123456789012345678901234567890123456789012 val str = "The good life is one inspired by love and guided by knowledge." val (n, m) = (21, 16) // An one-liner to set n = 21, m = 16
// Starting from n characters in and of m length assert("inspired by love" == str.slice(n, n + m)) // Starting from n characters in, up to the end of the string assert("inspired by love and guided by knowledge." == str.drop(n)) // Whole string minus last character assert("The good life is one inspired by love and guided by knowledge" == str.init) // Starting from a known character within the string and of m length assert("life is one insp" == str.dropWhile(_ != 'l').take(m) ) // Starting from a known substring within the string and of m length assert("good life is one" == { val i = str.indexOf("good"); str.slice(i, i + m) }) // Alternatively assert("good life is one" == str.drop(str.indexOf("good")).take(m))
}</lang>
Scheme
<lang scheme>(define s "Hello, world!") (define n 5) (define m (+ n 6))
(display (substring s n m)) (newline)
(display (substring s n)) (newline)
(display (substring s 0 (- (string-length s) 1))) (newline)
(display (substring s (string-index s #\o) m)) (newline)
(display (substring s (string-contains s "lo") m)) (newline)</lang>
Sed
<lang bash>
- 2 chars starting from 3rd
$ echo string | sed -r 's/.{3}(.{2}).*/\1/' in
- remove first 3 chars
echo string | sed -r 's/^.{3}//'
- delete last char
$ echo string | sed -r 's/.$//' strin
- `r' with two following chars
$ echo string | sed -r 's/.*(r.{2}).*/\1/' rin </lang>
Seed7
<lang seed7>$ include "seed7_05.s7i";
const proc: main is func
local const string: stri is "abcdefgh"; const integer: N is 2; const integer: M is 3; begin writeln(stri[N len M]); writeln(stri[N ..]); writeln(stri[.. pred(length(stri))]); writeln(stri[pos(stri, 'c') len M]); writeln(stri[pos(stri, "de") len M]); end func;</lang>
- Output:
bcd bcdefgh abcdefg cde def
SenseTalk
Note: SenseTalk indexes from 1 and ranges are inclusive <lang sensetalk>set mainString to "87654321" set n to 3 set m to 4 set c to "5" set sub to "654"
put characters n + 1 to n + m of mainString
put characters n + 1 to end of mainString
put characters first to penultimate of mainString
set characterOffset to offset of c in mainString put characters characterOffset to characterOffset + m - 1 of mainString
set subOffset to offset of sub in mainString put characters subOffset to subOffset + m - 1 of mainString </lang>
Sidef
<lang ruby>var str = 'abcdefgh'; var n = 2; var m = 3; say str.substr(n, m); #=> cde say str.substr(n); #=> cdefgh say str.substr(0, -1); #=> abcdefg say str.substr(str.index('d'), m); #=> def say str.substr(str.index('de'), m); #=> def</lang>
Slate
<lang slate>
- s := 'hello world shortest program'.
- n := 13.
- m := 4.
inform: (s copyFrom: n to: n + m). inform: (s copyFrom: n). inform: s allButLast. inform: (s copyFrom: (s indexOf: $w) to: (s indexOf: $w) + m). inform: (s copyFrom: (s indexOfSubSeq: 'ro') to: (s indexOfSubSeq: 'ro') + m). </lang>
Smalltalk
The distinction between searching a single character or a string into another string is rather blurred. In the following code, instead of using 'w' (a string) we could use $w (a character), but it makes no difference.
<lang smalltalk>|s| s := 'hello world shortest program'.
(s copyFrom: 13 to: (13+4)) displayNl. "4 is the length (5) - 1, since we need the index of the
last char we want, which is included"
(s copyFrom: 7) displayNl. (s allButLast) displayNl.
(s copyFrom: ((s indexOfRegex: 'w') first)
to: ( ((s indexOfRegex: 'w') first) + 4) ) displayNl.
(s copyFrom: ((s indexOfRegex: 'ro') first)
to: ( ((s indexOfRegex: 'ro') first) + 2) ) displayNl.</lang>
These last two examples in particular seem rather complex, so we can extend the string class.
<lang smalltalk>String extend [
copyFrom: index length: nChar [ ^ self copyFrom: index to: ( index + nChar - 1 ) ] copyFromRegex: regEx length: nChar [ |i| i := self indexOfRegex: regEx. ^ self copyFrom: (i first) length: nChar ]
].
"and show it simpler..."
(s copyFrom: 13 length: 5) displayNl. (s copyFromRegex: 'w' length: 5) displayNl. (s copyFromRegex: 'ro' length: 3) displayNl.</lang>
SNOBOL4
<lang snobol> string = "abcdefghijklmnopqrstuvwxyz" n = 12 m = 5 known_char = "q" known_str = "pq"
- starting from n characters in and of m length;
string len(n - 1) len(m) . output
- starting from n characters in, up to the end of the string;
string len(n - 1) rem . output
- whole string minus last character;
string rtab(1) . output
- starting from a known character within the string and of m length;
string break(known_char) len(m) . output
- starting from a known substring <= m within the string and of m length.
string (known_str len(m - size(known_str))) . output end</lang>
- Output:
lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy qrstu pqrst
SQL PL
In Db2, there are different ways to find the position of a character or substring. For this reason, several examples are shown. Please take a look at the documentation for more details. <lang sql pl> select 'the quick brown fox jumps over the lazy dog' from sysibm.sysdummy1; select substr('the quick brown fox jumps over the lazy dog', 5, 15) from sysibm.sysdummy1; select substr('the quick brown fox jumps over the lazy dog', 32) from sysibm.sysdummy1; select substr('the quick brown fox jumps over the lazy dog', 1, length ('the quick brown fox jumps over the lazy dog') - 1) from sysibm.sysdummy1;
select locate('j', 'the quick brown fox jumps over the lazy dog') from sysibm.sysdummy1; select locate_in_string('the quick brown fox jumps over the lazy dog', 'j') from sysibm.sysdummy1; select posstr('the quick brown fox jumps over the lazy dog', 'j') from sysibm.sysdummy1; select position('j', 'the quick brown fox jumps over the lazy dog', OCTETS) from sysibm.sysdummy1;
select substr('the quick brown fox jumps over the lazy dog', locate('j', 'the quick brown fox jumps over the lazy dog')) from sysibm.sysdummy1;
select locate('fox', 'the quick brown fox jumps over the lazy dog') from sysibm.sysdummy1; select locate_in_string('the quick brown fox jumps over the lazy dog', 'fox') from sysibm.sysdummy1; select posstr('the quick brown fox jumps over the lazy dog', 'fox') from sysibm.sysdummy1; select position('fox', 'the quick brown fox jumps over the lazy dog', OCTETS) from sysibm.sysdummy1;
select substr('the quick brown fox jumps over the lazy dog', locate('fox', 'the quick brown fox jumps over the lazy dog')) from sysibm.sysdummy1; </lang> Output:
db2 => select 'the quick brown fox jumps over the lazy dog' from sysibm.sysdummy1; 1 ------------------------------------------- the quick brown fox jumps over the lazy dog 1 record(s) selected. db2 => select substr('the quick brown fox jumps over the lazy dog', 5, 15) from sysibm.sysdummy1; 1 --------------- quick brown fox 1 record(s) selected. db2 => select substr('the quick brown fox jumps over the lazy dog', 32) from sysibm.sysdummy1; 1 ------------------------------------------- the lazy dog 1 record(s) selected. db2 => select substr('the quick brown fox jumps over the lazy dog', 1, length ('the quick brown fox jumps over the lazy dog') - 1) from sysibm.sysdummy1; 1 ------------------------------------------- the quick brown fox jumps over the lazy do 1 record(s) selected. db2 => select substr('the quick brown fox jumps over the lazy dog', locate('j', 'the quick brown fox jumps over the lazy dog')) from sysibm.sysdummy1; 1 ------------------------------------------- jumps over the lazy dog 1 record(s) selected. db2 => select substr('the quick brown fox jumps over the lazy dog', locate('fox', 'the quick brown fox jumps over the lazy dog')) from sysibm.sysdummy1; 1 ------------------------------------------- fox jumps over the lazy dog 1 record(s) selected.
Stata
<lang stata>s = "Ἐν ἀρχῇ ἐποίησεν ὁ θεὸς τὸν οὐρανὸν καὶ τὴν γῆν"
usubstr(s, 25, 11)
τὸν οὐρανὸν
usubstr(s, 25, .)
τὸν οὐρανὸν καὶ τὴν γῆν
usubstr(s, 1, ustrlen(s)-1)
Ἐν ἀρχῇ ἐποίησεν ὁ θεὸς τὸν οὐρανὸν καὶ τὴν γῆ
usubstr(s, -3, .)
γῆν</lang>
Swift
<lang swift> let string = "Hello, Swift language" let (n, m) = (5, 4)
// Starting from `n` characters in and of `m` length. do {
let start = string.startIndex.advancedBy(n) let end = start.advancedBy(m) // Pure-Swift (standard library only): _ = string[start..<end] // With Apple's Foundation framework extensions: string.substringWithRange(start..<end)
}
// Starting from `n` characters in, up to the end of the string. do {
// Pure-Swift (standard library only): _ = String( string.characters.suffix(string.characters.count - n) ) // With Apple's Foundation framework extensions: _ = string.substringFromIndex(string.startIndex.advancedBy(n))
}
// Whole string minus last character. do {
// Pure-Swift (standard library only): _ = String( string.characters.prefix( string.characters.count.predecessor() ) ) // With Apple's Foundation framework extensions: _ = string.substringToIndex(string.endIndex.predecessor())
}
// Starting from a known character within the string and of `m` length. do {
// Pure-Swift (standard library only): let character = Character("l") guard let characterIndex = string.characters.indexOf(character) else { fatalError("Index of '\(character)' character not found.") } let endIndex = characterIndex.advancedBy(m) _ = string[characterIndex..<endIndex]
}
// Starting from a known substring within the string and of `m` length. do {
// With Apple's Foundation framework extensions: let substring = "Swift" guard let range = string.rangeOfString(substring) else { fatalError("Range of substring \(substring) not found") } let start = range.startIndex let end = start.advancedBy(m) string[start..<end]
} </lang>
Tcl
<lang tcl>set str "abcdefgh" set n 2 set m 3
puts [string range $str $n [expr {$n+$m-1}]] puts [string range $str $n end] puts [string range $str 0 end-1]
- Because Tcl does substrings with a pair of indices, it is easier to express
- the last two parts of the task as a chained pair of [string range] operations.
- A maximally efficient solution would calculate the indices in full first.
puts [string range [string range $str [string first "d" $str] end] [expr {$m-1}]] puts [string range [string range $str [string first "de" $str] end] [expr {$m-1}]]
- From Tcl 8.5 onwards, these can be contracted somewhat.
puts [string range [string range $str [string first "d" $str] end] $m-1]
puts [string range [string range $str [string first "de" $str] end] $m-1]</lang>
Of course, if you were doing 'position-plus-length' a lot, it would be easier to add another subcommand to string
, like this:
<lang tcl># Define the substring operation, efficiently proc ::substring {string start length} {
string range $string $start [expr {$start + $length - 1}]
}
- Plumb it into the language
set ops [namespace ensemble configure string -map] dict set ops substr ::substring namespace ensemble configure string -map $ops
- Now show off by repeating the challenge!
set str "abcdefgh" set n 2 set m 3
puts [string substr $str $n $m] puts [string range $str $n end] puts [string range $str 0 end-1] puts [string substr $str [string first "d" $str] $m] puts [string substr $str [string first "de" $str] $m]</lang>
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT string="abcdefgh", n=4,m=n+2 substring=EXTRACT (string,#n,#m)
PRINT substring
substring=Extract (string,#n,0)
PRINT substring
substring=EXTRACT (string,0,-1)
PRINT substring
n=SEARCH (string,":d:"),m=n+2 substring=EXTRACT (string,#n,#m)
PRINT substring
substring=EXTRACT (string,":{substring}:"|,0)
PRINT substring
</lang>
- Output:
de defgh abcdefg de fgh
UNIX Shell
POSIX shells
<lang bash>str="abc qrdef qrghi" n=6 m=3
expr "x$str" : "x.\{$n\}\(.\{1,$m\}\)" expr "x$str" : "x.\{$n\}\(.*\)" printf '%s\n' "${str%?}" expr "r${str#*r}" : "\(.\{1,$m\}\)" expr "qr${str#*qr}" : "\(.\{1,$m\}\)"</lang>
def def qrghi abc qrdef qrgh rde qrd
This program uses expr(1) to capture a substring.
Bourne Shell
<lang bash>str="abc qrdef qrghi" n=6 m=3
expr "x$str" : "x.\{$n\}\(.\{1,$m\}\)" expr "x$str" : "x.\{$n\}\(.*\)" expr "x$str" : "x\(.*\)."
index() { i=0 s=$1 until test "x$s" = x || expr "x$s" : "x$2" >/dev/null; do i=`expr $i + 1` s=`expr "x$s" : "x.\(.*\)"` done echo $i } expr "x$str" : "x.\{`index "$str" r`\}\(.\{1,$m\}\)" expr "x$str" : "x.\{`index "$str" qr`\}\(.\{1,$m\}\)"</lang>
def def qrghi abc qrdef qrgh rde qrd
zsh
Note that the last two constructs won't work with bash as only zsh supports nested string manipulation. <lang bash>
- !/bin/zsh
string='abcdefghijk' echo ${string:2:3} # Display 3 chars starting 2 chars in ie: 'cde' echo ${string:2} # Starting 2 chars in, display to end of string echo ${string:0:${#string}-1} # Whole string minus last character echo ${string%?} # Shorter variant of the above echo ${${string/*c/c}:0:3} # Display 3 chars starting with 'c' echo ${${string/*cde/cde}:0:3} # Display 3 chars starting with 'cde' </lang>
Pipe
This example shows how to cut(1) a substring from a string.
<lang bash>#!/bin/sh str=abcdefghijklmnopqrstuvwxyz n=12 m=5
printf %s "$str" | cut -c $n-`expr $n + $m - 1` printf %s "$str" | cut -c $n- printf '%s\n' "${str%?}" printf q%s "${str#*q}" | cut -c 1-$m printf pq%s "${str#*pq}" | cut -c 1-$m</lang>
- Output:
$ sh substring.sh lmnop lmnopqrstuvwxyz abcdefghijklmnopqrstuvwxy qrstu pqrst
- cut -c counts characters from 1.
- cut(1) runs on each line of standard input, therefore the string must not contain a newline.
- One can use the old style `expr $n + $m - 1` or the new style $((n + m - 1)) to calculate the index.
- cut(1) prints the substring to standard output. To put the substring in a variable, use one of
- var=`printf %s "$str" | cut -c $n-\`expr $n + $m - 1\``
- var=$( printf %s "$str" | cut -c $n-$((n + m - 1)) )
Vala
<lang vala> string s = "Hello, world!"; int n = 1; int m = 3; // start at n and go m letters string s_n_to_m = s[n:n+m]; // start at n and go to end string s_n_to_end = s[n:s.length]; // start at beginning and show all but last string s_notlast = s[0:s.length - 1]; // start from known letter and then go m letters int index_of_l = s.index_of("l"); string s_froml_for_m = s[index_of_l:index_of_l + m]; // start from known substring then go m letters int index_of_lo = s.index_of("lo"); string s_fromlo_for_m = s[index_of_lo:index_of_lo + m]; </lang>
VBA
<lang vb>Public Sub substring()
'(1) starting from n characters in and of m length; '(2) starting from n characters in, up to the end of the string; '(3) whole string minus last character; '(4) starting from a known character within the string and of m length; '(5) starting from a known substring within the string and of m length.
sentence = "the last thing the man said was the" n = 10: m = 5 '(1) Debug.Print Mid(sentence, n, 5) '(2) Debug.Print Right(sentence, Len(sentence) - n + 1) '(3) Debug.Print Left(sentence, Len(sentence) - 1) '(4) k = InStr(1, sentence, "m") Debug.Print Mid(sentence, k, 5) '(5) k = InStr(1, sentence, "aid") Debug.Print Mid(sentence, k, 5)
End Sub</lang>
- Output:
thing thing the man said was the the last thing the man said was th man s aid w
VBScript
<lang vb> s = "rosettacode.org"
'starting from n characters in and of m length WScript.StdOut.WriteLine Mid(s,8,4)
'starting from n characters in, up to the end of the string WScript.StdOut.WriteLine Mid(s,8,Len(s)-7)
'whole string minus last character WScript.StdOut.WriteLine Mid(s,1,Len(s)-1)
'starting from a known character within the string and of m length WScript.StdOut.WriteLine Mid(s,InStr(1,s,"c"),4)
'starting from a known substring within the string and of m length WScript.StdOut.WriteLine Mid(s,InStr(1,s,"ose"),6) </lang>
- Output:
code code.org rosettacode.or code osetta
Wart
<lang python>s <- "abcdefgh" s.0 => "a"
- starting from n characters in and of m length;
def (substr s start len)
(s start start+len)
(substr s 3 2) => "de"
- starting from n characters in, up to the end of the string
(s 3 nil) => "defgh"
- whole string minus last character;
(s 3 -1) => "defg"
- starting from a known character within the string and of m length;
- starting from a known substring within the string and of m length.
let start (pos s pat)
(s start start+m)</lang>
Wren
<lang ecmascript>import "/fmt" for Str
var s = "αβγδεζηθ" var n = 2 var m = 3 var kc = "δ" // known character var ks = "δε" // known string // for reference System.print("Index of characters: 01234567") System.print("Complete string: %(s)") // starting from n characters in and of m length System.print("Start %(n), length %(m): %(Str.sub(s, n...n+m))") // starting from n characters in, up to the end of the string System.print("Start %(n), to end: %(Str.sub(s, n..-1))") // whole string minus last character System.print("All but last: %(Str.sub(s, 0..-2))") // starting from a known character within the string and of m length var dx = s.indexOf(kc) if (dx >= 0) {
System.print("Start '%(kc)', length %(m): %(Str.sub(s[dx..-1], 0...m))")
} // starting from a known substring within the string and of m length var sx = s.indexOf(ks) if (sx >= 0) {
System.print("Start '%(ks)', length %(m): %(Str.sub(s[sx..-1], 0...m))")
}</lang>
- Output:
Index of character: 01234567 Complete string: αβγδεζηθ Start 2, length 3: γδε Start 2, to end: γδεζηθ All but last: αβγδεζη Start 'δ', length 3: δεζ Start 'δε', length 3: δεζ
Yorick
<lang yorick>str = "abcdefgh"; n = 2; m = 3;
// starting from n character in and of m length write, strpart(str, n:n+m-1); // starting from n character in, up to the end of the string write, strpart(str, n:); // whole string minus last character write, strpart(str, :-1); // starting from a known character within the string and of m length match = strfind("d", str); write, strpart(str, [match(1), match(1)+m]); // starting from a known substring within the string and of m length match = strfind("cd", str); write, strpart(str, [match(1), match(1)+m]);</lang>
zkl
8 bit ASCII <lang zkl>var str = "abcdefgh", n = 2, m = 3; str[n,m] //-->"cde" str[n,*] //-->"cdefgh" str[0,-1] //-->"abcdefg" str[str.find("d"),m] //-->"def" str[str.find("de"),m] //-->"def"</lang>
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