Substring/Top and tail: Difference between revisions

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=={{header|Factor}}==
=={{header|Factor}}==
<lang factor>
<lang factor>USING: io kernel sequences ;
"Rosetta code" [ rest . ] [ but-last . ] [ rest but-last . ] tri
"Rosetta code" [ rest ] [ but-last ] [ rest but-last ] tri
</lang>
[ print ] tri@</lang>
{{out}}
{{out}}
<pre>
<pre>
"osetta code"
osetta code
"Rosetta cod"
Rosetta cod
"osetta cod"
osetta cod
</pre>
</pre>


Revision as of 16:02, 31 July 2018

Task
Substring/Top and tail
You are encouraged to solve this task according to the task description, using any language you may know.

The task is to demonstrate how to remove the first and last characters from a string.

The solution should demonstrate how to obtain the following results:

  • String with first character removed
  • String with last character removed
  • String with both the first and last characters removed


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.

360 Assembly

<lang 360asm>* Substring/Top and tail 04/03/2017 SUBSTRTT CSECT 

        USING  SUBSTRTT,R13       base register
        B      72(R15)            skip savearea
        DC     17F'0'             savearea
        STM    R14,R12,12(R13)    save previous context
        ST     R13,4(R15)         link backward
        ST     R15,8(R13)         link forward
        LR     R13,R15            set addressability

        XPRNT  S8,L'S8            print s8
        MVC    S7,S8+1            s7=substr(s8,2,7)
        XPRNT  S7,L'S7            print s7
        MVC    S7,S8              s7=substr(s8,1,7)
        XPRNT  S7,L'S7            print s7
        MVC    S6,S8+1            s6=substr(s8,2,6)
        XPRNT  S6,L'S6            print s6

        L      R13,4(0,R13)       epilog
        LM     R14,R12,12(R13)    restore previous context
        XR     R15,R15            rc=0
        BR     R14                exit

S8 DC CL8'12345678' S7 DS CL7 S6 DS CL6 

        YREGS
        END    SUBSTRTT</lang>
Output:
12345678
2345678
1234567
234567

ACL2

<lang Lisp>(defun str-rest (str) 

  (coerce (rest (coerce str 'list)) 'string))

(defun rdc (xs) 

  (if (endp (rest xs))
      nil
      (cons (first xs)
            (rdc (rest xs)))))

(defun str-rdc (str) 

  (coerce (rdc (coerce str 'list)) 'string))

(str-rdc "string") (str-rest "string") (str-rest (str-rdc "string"))</lang>

Ada

<lang Ada>with Ada.Text_IO;

procedure Remove_Characters is 

  S: String := "upraisers";
  use Ada.Text_IO;

begin 

  Put_Line("Full String:   """ & S & """");
  Put_Line("Without_First: """ & S(S'First+1 .. S'Last) & """");
  Put_Line("Without_Last:  """ & S(S'First   .. S'Last-1) & """");
  Put_Line("Without_Both:  """ & S(S'First+1 .. S'Last-1) & """");

end Remove_Characters;</lang>

Output: 

Full String:   "upraisers"
Without_First: "praisers"
Without_Last:  "upraiser"
Without_Both:  "praiser"

With UTF8 support in Ada 2012 (Wide_Character of literals is automatic):

<lang Ada>with Ada.Text_IO; with Ada.Strings.UTF_Encoding.Wide_Strings;

procedure Remove_Characters is 

  use Ada.Text_IO;
  use Ada.Strings.UTF_Encoding;
  use Ada.Strings.UTF_Encoding.Wide_Strings;
  
  S : String := "upraisers";
  U : Wide_String := Decode (UTF_8_String'(S));
  
  function To_String (X : Wide_String)return String
  is
  begin
     return String (UTF_8_String'(Encode (X)));
  end To_String;

begin 

  Put_Line
    (To_String
       ("Full String:   """ & U & """"));
  Put_Line
    (To_String
       ("Without_First: """ & U (U'First + 1 .. U'Last) & """"));
  Put_Line
    (To_String
       ("Without_Last:  """ & U (U'First   .. U'Last - 1) & """"));
  Put_Line
    (To_String
       ("Without_Both:  """ & U (U'First + 1 .. U'Last - 1) & """"));

end Remove_Characters;</lang>

Output: 

Full String:   "upraisers"
Without_First: "praisers"
Without_Last:  "upraiser"
Without_Both:  "praiser"

Aime

<lang aime>o_text(delete("knights", 0)); o_newline(); o_text(delete("knights", -1)); o_newline(); o_text(delete(delete("knights", 0), -1)); o_newline();</lang>

Output:
nights
knight
night

Apex

<lang java> String strOrig = 'brooms'; String str1 = strOrig.substring(1, strOrig.length()); system.debug(str1); String str2 = strOrig.substring(0, strOrig.length()-1); system.debug(str2); String str3 = strOrig.substring(1, strOrig.length()-1); system.debug(str3);

// Regular Expressions approach String strOrig = 'brooms'; String str1 = strOrig.replaceAll( '^.', ); system.debug(str1); String str2 = strOrig.replaceAll( '.$', ) ; system.debug(str2); String str3 = strOrig.replaceAll( '^.|.$', ); system.debug(str3); </lang>

Output:
rooms

broom

room

ALGOL 68

Translation of: AWK
Works with: ALGOL 68 version Revision 1 - no extensions to language used.
Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny.

<lang algol68>#!/usr/local/bin/a68g --script #

STRING str="upraisers"; printf(($gl$, 

 str,                      # remove no characters #
 str[LWB str+1:         ], # remove the first character #
 str[         :UPB str-1], # remove the last character #
 str[LWB str+1:UPB str-1], # remove both the first and last character #
 str[LWB str+2:         ], # remove the first 2 characters #
 str[         :UPB str-2], # remove the last 2 characters #
 str[LWB str+1:UPB str-2], # remove 1 before and 2 after #
 str[LWB str+2:UPB str-1], # remove 2 before and one after #
 str[LWB str+2:UPB str-2]  # remove both the first and last 2 characters #

))</lang> Output: 

upraisers
praisers
upraiser
praiser
raisers
upraise
praise
raiser
raise

AutoHotkey

<lang AutoHotkey>myString := "knights" MsgBox % SubStr(MyString, 2) MsgBox % SubStr(MyString, 1, StrLen(MyString)-1) MsgBox % SubStr(MyString, 2, StrLen(MyString)-2)</lang>

AWK

<lang awk>BEGIN { 

 mystring="knights"
 print substr(mystring,2)                       # remove the first letter
 print substr(mystring,1,length(mystring)-1)    # remove the last character
 print substr(mystring,2,length(mystring)-2)    # remove both the first and last character

}</lang>

BASIC

<lang basic>10 PRINT FN F$("KNIGHTS"): REM STRIP THE FIRST LETTER 20 PRINT FN L$("SOCKS"): REM STRIP THE LAST LETTER 30 PRINT FN B$("BROOMS"): REM STRIP BOTH THE FIRST AND LAST LETTER 100 END

9000 DEF FN F$(A$)=RIGHT$(A$,LEN(A$)-1) 9010 DEF FN L$(A$)=LEFT$(A$,LEN(A$)-1) 9020 DEF FN B$(A$)=FN L$(FN F$(A$))</lang>

Sinclair ZX81 BASIC

Note that strings are indexed from 1. <lang basic>10 REM STRING SLICING EXAMPLE 20 LET S$="KNIGHTS" 30 REM WITH FIRST CHARACTER REMOVED: 40 PRINT S$(2 TO ) 50 REM WITH LAST CHARACTER REMOVED: 60 PRINT S$( TO LEN S$-1) 70 REM WITH BOTH REMOVED: 80 PRINT S$(2 TO LEN S$-1)</lang>

Output:
NIGHTS
KNIGHT
NIGHT

Bracmat

Bracmat uses UTF-8 internally. The function utf fails if its argument isn't a valid UTF-8 multibyte string, but in two slightly different ways: an indefinite and a definite way. If the argument does not have the required number of bytes but otherwise seems to be ok, Bracmat's backtacking mechanism lenghtens the argument and then calls utf again. This is repeated until utf either succeeds or definitely fails. The code is far from efficient.

<lang bracmat>(substringUTF-8= 

 @( Δημοτική
  : (%?a&utf$!a) ?"String with first character removed"
  )

& @( Δημοτική 

  : ?"String with last character removed" (?z&utf$!z)
  )

& @( Δημοτική 

  :   (%?a&utf$!a)
      ?"String with both the first and last characters removed"
      (?z&utf$!z)
  )

& out 

 $ ("String with first character removed:" !"String with first character removed")

& out 

 $ ("String with last character removed:" !"String with last character removed")

& out 

 $ ( "String with both the first and last characters removed:"
     !"String with both the first and last characters removed"
   ));</lang>

!substringUTF-8
String with first character removed: ημοτική
String with last character removed: Δημοτικ
String with both the first and last characters removed: ημοτικ

If the string is known to consist of 8-byte characters, we can use a simpler method. Essential are the % and @ prefixes. The % prefix matches 1 or more elements (bytes, in the case of string pattern matching), while @ matches 0 or 1 elements. In combination these prefixes match 1 and only 1 byte.

<lang bracmat>(substring-8-bit= 

 @("8-bit string":%@ ?"String with first character removed")

& @("8-bit string":?"String with last character removed" @) & @( "8-bit string" 

  : %@ ?"String with both the first and last characters removed" @
  )

& out 

 $ ("String with first character removed:" !"String with first character removed")

& out 

 $ ("String with last character removed:" !"String with last character removed")

& out 

 $ ( "String with both the first and last characters removed:"
     !"String with both the first and last characters removed"
   ));</lang>

!substring-8-bit
String with first character removed: -bit string
String with last character removed: 8-bit strin
String with both the first and last characters removed: -bit strin

BBC BASIC

<lang bbcbasic> s$ = "Rosetta Code" 

     PRINT MID$(s$, 2)
     PRINT LEFT$(s$)
     PRINT LEFT$(MID$(s$, 2))</lang>

Burlesque

<lang blsq> blsq ) "RosettaCode"[- "osettaCode" blsq ) "RosettaCode"-] 'R blsq ) "RosettaCode"~] "RosettaCod" blsq ) "RosettaCode"[~ 'e blsq ) "RosettaCode"~- "osettaCod" </lang>

C

<lang c>#include <string.h>

  1. include <stdlib.h>
  2. include <stdio.h>

int main( int argc, char ** argv ){ 

 const char * str_a = "knight";
 const char * str_b = "socks";
 const char * str_c = "brooms";

 char * new_a = malloc( strlen( str_a ) - 1 );
 char * new_b = malloc( strlen( str_b ) - 1 );
 char * new_c = malloc( strlen( str_c ) - 2 );

 strcpy( new_a, str_a + 1 );
 strncpy( new_b, str_b, strlen( str_b ) - 1 );
 strncpy( new_c, str_c + 1, strlen( str_c ) - 2 );

 printf( "%s\n%s\n%s\n", new_a, new_b, new_c );

 free( new_a );
 free( new_b );
 free( new_c );

 return 0;

}</lang>

Result: 

night
sock
room

ANSI C provides little functionality for text manipulation outside of string.h. While a number of libraries for this purpose have been written, this example uses only ANSI C.

C++

<lang cpp>#include <string>

  1. include <iostream>

int main( ) { 

  std::string word( "Premier League" ) ;
  std::cout << "Without first letter: " << word.substr( 1 ) << " !\n" ;
  std::cout << "Without last letter: " << word.substr( 0 , word.length( ) - 1 ) << " !\n" ;
  std::cout << "Without first and last letter: " << word.substr( 1 , word.length( ) - 2 ) << " !\n" ;
  return 0 ;

}</lang> Output: 

Without first letter: remier League !
Without last letter: Premier Leagu !
Without first and last letter: remier Leagu !

C#

<lang C sharp> using System;

class Program { 

   static void Main(string[] args)
   {
       string testString = "test";
       Console.WriteLine(testString.Substring(1));
       Console.WriteLine(testString.Substring(0, testString.Length - 1));
       Console.WriteLine(testString.Substring(1, testString.Length - 2));
   }

} </lang>

Result: 

est
tes
es

Clojure

<lang clojure>; using substring: user=> (subs "knight" 1) "night" user=> (subs "socks" 0 4) "sock" user=> (.substring "brooms" 1 5) "room"

using rest and drop-last

user=> (apply str (rest "knight")) "night" user=> (apply str (drop-last "socks")) "sock" user=> (apply str (rest (drop-last "brooms"))) "room"</lang>

Common Lisp

subseq will signal an error if you provide invalid start or end values. <lang lisp>> (defvar *str* "∀Ꮺ✤Л◒")

  • STR*

> (subseq *str* 1) ; remove first character "Ꮺ✤Л◒" > (subseq *str* 0 (1- (length *str*))) ; remove last character "∀Ꮺ✤Л" > (subseq *str* 1 (1- (length *str*))) ; remove first and last character "Ꮺ✤Л"</lang>

D

Version for ASCII strings or Unicode dstrings: <lang d>import std.stdio;

void main() { 

   // strip first character
   writeln("knight"[1 .. $]);

   // strip last character
   writeln("socks"[0 .. $ - 1]);

   // strip both first and last characters
   writeln("brooms"[1 .. $ - 1]);

}</lang>

Output:
night
sock
room

Delphi

<lang Delphi>program TopAndTail;

{$APPTYPE CONSOLE}

const 

 TEST_STRING = '1234567890';

begin 

 Writeln(TEST_STRING);                                    // full string
 Writeln(Copy(TEST_STRING, 2, Length(TEST_STRING)));      // first character removed
 Writeln(Copy(TEST_STRING, 1, Length(TEST_STRING) - 1));  // last character removed
 Writeln(Copy(TEST_STRING, 2, Length(TEST_STRING) - 2));  // first and last characters removed

 Readln;

end.</lang>

Eero

<lang objc>#import <Foundation/Foundation.h>

int main() 

 autoreleasepool

   s := 'knight'
   Log( '%@', s[1 .. s.length-1] )  // strip first character

   s = 'socks'
   Log( '%@', s[0 .. s.length-2] )  // strip last character
  
   s = 'brooms'   
   Log( '%@', s[1 .. s.length-2] )  // strip both first and last characters

   s = 'Δημοτική'   
   Log( '%@', s[1 .. s.length-2] )  // strip both first and last characters

 return 0</lang>

Output:

2013-09-04 17:08:09.453 a.out[2257:507] night
2013-09-04 17:08:09.454 a.out[2257:507] sock
2013-09-04 17:08:09.454 a.out[2257:507] room
2013-09-04 17:08:09.455 a.out[2257:507] ημοτικ

Elena

ELENA 3.2 : <lang elena>import extensions.

program = [ 

   var testString := "test".
   
   console printLine(testString Substring(1)).
   console printLine(testString Substring(0, testString length - 1)).
   console printLine(testString Substring(1, testString length - 2)).

].</lang>

Output:
est
tes
es

Elixir

<lang elixir>iex(1)> str = "abcdefg" "abcdefg" iex(2)> String.slice(str, 1..-1) "bcdefg" iex(3)> String.slice(str, 0..-2) "abcdef" iex(4)> String.slice(str, 1..-2) "bcdef"</lang>

Emacs Lisp

<lang Emacs Lisp> (progn 

 (setq string "top and tail")
 (insert (format "%s\n" string) )
 (setq len (length string) )
 (insert (format "%s\n" (substring string 1) ))
 (insert (format "%s\n" (substring string 0 (1- len) )))
 (insert (format "%s\n" (substring string 1 (1- len) ))))

</lang> Output: 

top and tail
op and tail
top and tai
op and tai

Erlang

<lang erlang>1> Str = "Hello". "Hello" 2> string:sub_string(Str, 2).  % To strip the string from the right by 1 "ello" 3> string:sub_string(Str, 1, length(Str)-1).  % To strip the string from the left by 1 "Hell" 4> string:sub_string(Str, 2, length(Str)-1).  % To strip the string from both sides by 1 "ell"</lang>

Euphoria

<lang euphoria>function strip_first(sequence s) 

   return s[2..$]

end function

function strip_last(sequence s) 

   return s[1..$-1]

end function

function strip_both(sequence s) 

   return s[2..$-1]

end function

puts(1, strip_first("knight")) -- strip first character puts(1, strip_last("write")) -- strip last character puts(1, strip_both("brooms")) -- strip both first and last characters</lang>


F#

<lang fsharp>[<EntryPoint>] let main args = 

   let s = "一二三四五六七八九十"
   printfn "%A" (s.Substring(1))
   printfn "%A" (s.Substring(0, s.Length - 1))
   printfn "%A" (s.Substring(1, s.Length - 2))
   0</lang>

Output 

"二三四五六七八九十"
"一二三四五六七八九"
"二三四五六七八九"

Factor

<lang factor>USING: io kernel sequences ; "Rosetta code" [ rest ] [ but-last ] [ rest but-last ] tri [ print ] tri@</lang>

Output:
osetta code
Rosetta cod
osetta cod

Forth

In Forth, strings typically take up two cells on the stack, diagrammed ( c-addr u ), with C-ADDR the address of the string and U its length. Dropping leading and trailing characters then involves simple mathematical operations on the address or length, without mutating or copying the string.

<lang forth>: hello ( -- c-addr u ) 

 s" Hello" ;

hello 1 /string type \ => ello

hello 1- type \ => hell

hello 1 /string 1- type \ => ell</lang>

This works for ASCII, and a slight variation (2 instead of 1 per character) will suffice for BIG5, GB2312, and like, but Unicode-general code can use +X/STRING and X\STRING- from Forth-200x's XCHAR wordset.

Fortran

<lang Fortran>program substring 

 character(len=5) :: string
 string = "Hello"
 
 write (*,*) string
 write (*,*) string(2:)
 write (*,*) string( :len(string)-1)
 write (*,*) string(2:len(string)-1)

end program substring</lang>

FreeBASIC

<lang freebasic>' FB 1.05.0 Win64

Dim s As String = "panda" Dim s1 As String = Mid(s, 2) Dim s2 As String = Left(s, Len(s) - 1) Dim s3 As String = Mid(s, 2, Len(s) - 2) Print s Print s1 Print s2 Print s3 Sleep</lang>

Output:
panda
anda
pand
and

Go

Go strings are byte arrays that can hold whatever you want them to hold. Common contents are ASCII and UTF-8. You use different techniques depending on how you are interpreting the string. The utf8 package functions shown here allows efficient extraction of first and last runes without decoding the entire string. <lang go>package main

import ( 

   "fmt"
   "unicode/utf8"

)

func main() { 

   // ASCII contents:  Interpreting "characters" as bytes.
   s := "ASCII"
   fmt.Println("String:                ", s)
   fmt.Println("First byte removed:    ", s[1:])
   fmt.Println("Last byte removed:     ", s[:len(s)-1])
   fmt.Println("First and last removed:", s[1:len(s)-1])
   // UTF-8 contents:  "Characters" as runes (unicode code points)
   u := "Δημοτική"
   fmt.Println("String:                ", u)
   _, sizeFirst := utf8.DecodeRuneInString(u)
   fmt.Println("First rune removed:    ", u[sizeFirst:])
   _, sizeLast := utf8.DecodeLastRuneInString(u)
   fmt.Println("Last rune removed:     ", u[:len(u)-sizeLast])
   fmt.Println("First and last removed:", u[sizeFirst:len(u)-sizeLast])

}</lang> Output: 

String:                 ASCII
First byte removed:     SCII
Last byte removed:      ASCI
First and last removed: SCI
String:                 Δημοτική
First rune removed:     ημοτική
Last rune removed:      Δημοτικ
First and last removed: ημοτικ

GW-BASIC

<lang qbasic>10 A$="knight":B$="socks":C$="brooms" 20 PRINT MID$(A$,2) 30 PRINT LEFT$(B$,LEN(B$)-1) 40 PRINT MID$(C$,2,LEN(C$)-2)</lang>

Groovy

Solution: <lang groovy>def top = { it.size() > 1 ? it[0..-2] : } def tail = { it.size() > 1 ? it[1..-1] : }</lang>

Test: <lang groovy>def testVal = 'upraisers' println """ original: ${testVal} top: ${top(testVal)} tail: ${tail(testVal)} top&tail: ${tail(top(testVal))} """</lang>

Output: 

original: upraisers
top:      upraiser
tail:     praisers
top&tail: praiser

Haskell

<lang Haskell>-- We define the functions to return an empty string if the argument is too -- short for the particular operation.

remFirst, remLast, remBoth :: String -> String

remFirst "" = "" remFirst cs = tail cs

remLast "" = "" remLast cs = init cs

remBoth (c:cs) = remLast cs remBoth _ = ""

main :: IO () main = do 

 let s = "Some string."  
 mapM_ (\f -> putStrLn . f $ s) [remFirst, remLast, remBoth]</lang>

Alternative solution with builtin functions: <lang Haskell>word = "knights"

main = do 

   -- You can drop the first item
   -- using `tail`
   putStrLn (tail word)

   -- The `init` function will drop
   -- the last item
   putStrLn (init word)

   -- We can combine these two to drop
   -- the last and the first characters
   putStrLn (middle word)

-- You can combine functions using `.`, -- which is pronounced "compose" or "of" middle = init . tail</lang>

In short: <lang Haskell>main :: IO () main = mapM_ print $ [tail, init, init . tail] <*> ["knights"]</lang>

Output:
"nights"
"knight"
"night"

Icon and Unicon

The task is accomplished by sub-stringing. <lang Icon>procedure main() write(s := "knight"," --> ", s[2:0]) # drop 1st char write(s := "sock"," --> ", s[1:-1]) # drop last write(s := "brooms"," --> ", s[2:-1]) # drop both end</lang>

It could also be accomplished (less clearly) by assigning into the string as below. Very awkward for both front and back. <lang Icon>write(s := "knight"," --> ", s[1] := "", s) # drop 1st char</lang>

J

The monadic primitives }. (Behead) and }: (Curtail) are useful for this task.

Example use:
<lang j> }. 'knight' NB. drop first item night 

  }: 'socks'       NB. drop last item

sock 

  }: }. 'brooms'   NB. drop first and last items

room</lang>

Java

I solve this problem two ways. First I use substring which is relatively fast for small strings, since it simply grabs the characters within a set of given bounds. The second uses regular expressions, which have a higher overhead for such short strings.

<lang Java>public class RM_chars { 

 public static void main( String[] args ){
   System.out.println( "knight".substring( 1 ) );
   System.out.println( "socks".substring( 0, 4 ) );
   System.out.println( "brooms".substring( 1, 5 ) );
     // first, do this by selecting a specific substring
     // to exclude the first and last characters
   
   System.out.println( "knight".replaceAll( "^.", "" ) );
   System.out.println( "socks".replaceAll( ".$", "" ) );
   System.out.println( "brooms".replaceAll( "^.|.$", "" ) );
     // then do this using a regular expressions
 }

}</lang>

Results: 

night
sock
room
night
sock
room

JavaScript

<lang javascript>alert("knight".slice(1)); // strip first character alert("socks".slice(0, -1)); // strip last character alert("brooms".slice(1, -1)); // strip both first and last characters</lang>

jq

jq uses 0-based indexing, so [1:] yields all but the first character, it being understood that data strings in jq are JSON strings. [0:-1], which can be abbreviated to [:-1], yields all but the last character, and so on. Here are some examples:<lang jq>"一二三四五六七八九十"[1:]' => "二三四五六七八九十"

"一二三四五六七八九十"[:-1]' => "一二三四五六七八九"

"一二三四五六七八九十"[1:-1]' => "二三四五六七八九"

"a"[1:-1] # => "" </lang> Recent versions of jq also have regular expression support, with named captures. This leads to many other possibilities, e.g.<lang jq>"abc" | capture( ".(?<monkey>.*)." ).monkey => "b"</lang>

Julia

<lang julia>julia> "My String"[2:end] # without first character "y String"

julia> "My String"[1:end-1] # without last character "My Strin"

julia> "My String"[2:end-1] # without first and last characters "y Strin"</lang>

Kotlin

<lang scala>// version 1.0.6 fun main(args: Array<String>) { 

   val s = "Rosetta"
   println(s.drop(1))
   println(s.dropLast(1))
   println(s.drop(1).dropLast(1))

}</lang>

Output:
osetta
Rosett
osett

Lasso

<lang Lasso>local(str = 'The quick grey rhino jumped over the lazy green fox.')

// String with first character removed string_remove(#str,-startposition=1,-endposition=1)

// String with last character removed string_remove(#str,-startposition=#str->size,-endposition=#str->size)

// String with both the first and last characters removed string_remove(string_remove(#str,-startposition=#str->size,-endposition=#str->size),-startposition=1,-endposition=1)</lang>

Output:
he quick grey rhino jumped over the lazy green fox.
The quick grey rhino jumped over the lazy green fox
he quick grey rhino jumped over the lazy green fox

<lang Lasso>local(mystring = 'ÅÜÄÖカ')

  1. mystring -> remove(1,1)
  2. mystring

'
'

  1. mystring -> remove(#mystring -> size,1)
  2. mystring

'
'

  1. mystring -> remove(1,1)& -> remove(#mystring -> size,1)
  2. mystring</lang>

-> ÜÄÖカ

ÜÄÖ

Ä

Liberty BASIC

<lang lb>string$ = "Rosetta Code" Print Mid$(string$, 2) Print Left$(string$, (Len(string$) - 1)) Print Mid$(string$, 2, (Len(string$) - 2))</lang>

LiveCode

<lang LiveCode>put "pple" into x answer char 2 to len(x) of x // pple answer char 1 to -2 of x // ppl answer char 2 to -2 of x // ppl</lang>

Locomotive Basic

<lang locobasic>10 a$="knight":b$="socks":c$="brooms" 20 PRINT MID$(a$,2) 30 PRINT LEFT$(b$,LEN(b$)-1) 40 PRINT MID$(c$,2,LEN(c$)-2)</lang>

Lasso

<lang Lasso>local(str = 'The quick grey rhino jumped over the lazy green fox.')

// String with first character removed string_remove(#str,-startposition=1,-endposition=1) // > he quick grey rhino jumped over the lazy green fox.

// String with last character removed string_remove(#str,-startposition=#str->size,-endposition=#str->size) // > The quick grey rhino jumped over the lazy green fox

// String with both the first and last characters removed string_remove(string_remove(#str,-startposition=#str->size,-endposition=#str->size),-startposition=1,-endposition=1) // > he quick grey rhino jumped over the lazy green fox</lang>

<lang logo>make "s "|My string| print butfirst :s print butlast :s print butfirst butlast :s</lang>

Logtalk

Using atoms for representing strings: <lang logtalk>

- object(top_and_tail).
   :- public(test/1).
   test(String) :-
       sub_atom(String, 1, _, 0, MinusTop),
       write('String with first character cut: '), write(MinusTop), nl,
       sub_atom(String, 0, _, 1, MinusTail),
       write('String with last character cut: '), write(MinusTail), nl,
       sub_atom(String, 1, _, 1, MinusTopAndTail),
       write('String with first and last characters cut: '), write(MinusTopAndTail), nl.
- end_object.

</lang> Sample output: <lang text> | ?- top_and_tail::test('Rosetta'). String with first character cut: osetta String with last character cut: Rosett String with first and last characters cut: osett yes </lang>

Lua

<lang lua>print (string.sub("knights",2)) -- remove the first character print (string.sub("knights",1,-2)) -- remove the last character print (string.sub("knights",2,-2)) -- remove the first and last characters</lang>

Maple

There are several ways to do this. The first is, I think, the simplest. <lang Maple>> s := "some string": > s[2..-1]; 

                             "ome string"

> s[1..-2]; 

                             "some strin"

> s[2..-2]; 

                             "ome strin"</lang>

The same functionality exists in the form of a procedure: <lang Maple>> substring( s, 2 .. -1 ); 

                             "ome string"

> substring( s, 1 .. -2 ); 

                             "some strin"

> substring( s, 2 .. -2 ); 

                             "ome strin"</lang>

Furthermore, there is a slightly different version in the "StringTools" package: <lang Maple>> use StringTools in > SubString( s, 2 .. -1 ); > SubString( s, 1 .. -1 ); > SubString( s, 2 .. -2 ) > end use; 

                             "ome string"

                            "some string"

                             "ome strin"</lang>

(The difference between "substring" and "StringTools:-SubString" lies in how each treats a name as input; the former returns a name, while the latter returns a string.)

Mathematica

<lang Mathematica>StringDrop["input string",1] StringDrop["input string",-1] StringTake["input string",{2,-2}] </lang>

MATLAB / Octave

The following case will not handle UTF-8. However, Matlab supports conversion of utf-8 to utf-16 using native2unicode(). <lang MATLAB> 

   % String with first character removed

str(2:end) 

   % String with last character removed

str(1:end-1) 

   % String with both the first and last characters removed

str(2:end-1) </lang>

Nemerle

<lang Nemerle>using System; using System.Console;

module RemoveChars { 

   Main() : void
   {
       def str = "*A string*";
       def end = str.Remove(str.Length - 1);  // from pos to end
       def beg = str.Remove(0, 1);            // start pos, # of chars to remove
       def both = str.Trim(array['*']);       // with Trim() you need to know what char's you're removing
       
       WriteLine($"$str -> $beg -> $end -> $both");
   }

}</lang>

NetRexx

<lang netrexx>/**********************************************************************

  • 02.08.2013 Walter Pachl translated from REXX
                                                                                                                                            • /

z = 'abcdefghijk' l=z.length() say ' the original string =' z If l>=1 Then Do 

 Say 'string first        character removed =' z.substr(2)
 say 'string         last character removed =' z.left(l-1)
 End

If l>=2 Then 

 Say 'string first & last character removed =' z.substr(2,l-2)</lang>

NewLISP

<lang NewLISP>(let (str "rosetta") 

 ;; strip first char
 (println (1 str))
 ;; strip last char
 (println (0 -1 str))
 ;; strip both first and last characters
 (println (1 -1 str)))</lang>

Nim

<lang nim>var s = "The quick μ brown fox" echo(s.substr(1)) echo(s.substr(0,s.len-2)) echo(s.substr(1,s.len-2))

  1. using slices

echo(s[1 .. -2])</lang>

Output:
he quick μ brown fox
The quick μ brown fo
he quick μ brown fo
he quick μ brown fo

Objeck

<lang objeck> bundle Default { 

  class TopTail {
     function : Main(args : System.String[]) ~ Nil {
        string := "test";
        string->SubString(1, string->Size() - 1)->PrintLine();
        string->SubString(string->Size() - 1)->PrintLine();
        string->SubString(1, string->Size() - 2)->PrintLine();
     }
  }

} </lang>

OCaml

<lang ocaml>let strip_first_char str = 

 if str = "" then "" else
 String.sub str 1 ((String.length str) - 1)

let strip_last_char str = 

 if str = "" then "" else
 String.sub str 0 ((String.length str) - 1)

let strip_both_chars str = 

 match String.length str with
 | 0 | 1 | 2 -> ""
 | len -> String.sub str 1 (len - 2)

let () = 

 print_endline (strip_first_char "knight");
 print_endline (strip_last_char "socks");
 print_endline (strip_both_chars "brooms");
</lang>

Oforth

<lang Oforth>: topAndTail(s) 

   s right(s size 1-) println
   s left(s size 1-) println
   s extract(2, s size 1- ) println ;</lang>
Output:
topAndTail("MyString")
yString
MyStrin
yStrin

PARI/GP

<lang parigp>df(s)=concat(vecextract(Vec(s),1<<#s-2)); dl(s)=concat(vecextract(Vec(s),1<<(#s-1)-1)); db(s)=concat(vecextract(Vec(s),1<<(#s-1)-2));</lang>

Pascal

See Delphi

Perl

<lang perl>print substr("knight",1), "\n"; # strip first character print substr("socks", 0, -1), "\n"; # strip last character print substr("brooms", 1, -1), "\n"; # strip both first and last characters</lang>

In perl, we can also remove the last character from a string variable with the chop function:

<lang perl>$string = 'ouch'; $bits = chop($string); # The last letter is returned by the chop function print $bits; # h print $string; # ouc # See we really did chop the last letter off</lang>

Perl 6

Perl 6 provides both functional and method forms of substr. Note that, unlike in Perl 5, offsets from the end do not use negative numbers, but instead require a function expressing the negative offset relative to the length parameter, which is supplied by the operator. The form *-1 is just a simple way to write such a function.

We use musical sharps and flats to illustrate that Perl is comfortable with characters from any Unicode plane.

<lang perl6>my $s = '𝄪♯♮♭𝄫';

print qq:to/END/; 

   Original:
   $s

   Remove first character:
   { substr($s, 1) }
   { $s.substr(1) }

   Remove last character:
   { substr($s, 0, *-1) }
   { $s.substr( 0, *-1) }
   { $s.chop }

   Remove first and last characters:
   { substr($s, 1, *-1) }
   { $s.substr(1, *-1) }
   END</lang>
Output:
Original:
𝄪♯♮♭𝄫

Remove first character:
♯♮♭𝄫
♯♮♭𝄫
 
Remove last character:
𝄪♯♮♭
𝄪♯♮♭
𝄪♯♮♭
 
Remove first and last characters:
♯♮♭
♯♮♭

Phix

<lang Phix>constant s = "(test)" ?s[2..-1] ?s[1..-2] ?s[2..-2]</lang>

Output:
"test)"
"(test"
"test"

PHP

<lang php><?php echo substr("knight", 1), "\n"; // strip first character echo substr("socks", 0, -1), "\n"; // strip last character echo substr("brooms", 1, -1), "\n"; // strip both first and last characters ?></lang>

PicoLisp

<lang PicoLisp>: (pack (cdr (chop "knight"))) # Remove first character -> "night"

(pack (head -1 (chop "socks"))) # Remove last character

-> "sock"

(pack (cddr (rot (chop "brooms")))) # Remove first and last characters

-> "room"</lang>

PL/I

<lang PL/I> declare s character (100) varying; s = 'now is the time to come to the aid of the party'; if length(s) <= 2 then stop; put skip list ('First character removed=' || substr(s,2) ); put skip list ('Last character removed=' || substr(s, 1, length(s)-1) ); put skip list ('One character from each end removed=' || 

  substr(s, 2, length(s)-2) );

</lang> OUTPUT: 

First character removed=ow is the time to come to the aid of the party
Last character removed=now is the time to come to the aid of the part 
One character from each end removed=ow is the time to come to the aid of the part

PowerShell

Works with: PowerShell version 4.0

First method

<lang PowerShell> $string = "top and tail" $string $string.Substring(1) $string.Substring(0, $string.Length - 1) $string.Substring(1, $string.Length - 2) </lang>

Second method

<lang PowerShell> $string = "top and tail" $string $string[1..($string.Length - 1)] -join "" $string[0..($string.Length - 2)] -join "" $string[1..($string.Length - 2)] -join "" </lang> Output: 

top and tail
op and tail
top and tai
op and tai

Prolog

Works with SWI-Prolog.

<lang Prolog>remove_first_last_chars :- L = "Rosetta", L = [_|L1], remove_last(L, L2), remove_last(L1, L3), writef('Original string  : %s\n', [L]), writef('Without first char  : %s\n', [L1]), writef('Without last char  : %s\n', [L2]), writef('Without first/last chars : %s\n', [L3]).

remove_last(L, LR) :- append(LR, [_], L).</lang> Output : 

 ?- remove_first_last_chars.
Original string          : Rosetta
Without first char       : osetta
Without last char        : Rosett
Without first/last chars : osett
true.

PureBasic

<lang PureBasic>If OpenConsole() 

 PrintN(Right("knight", Len("knight") - 1))  ;strip the first letter
 PrintN(Left("socks", Len("socks")- 1))      ;strip the last letter
 PrintN(Mid("brooms", 2, Len("brooms") - 2)) ;strip both the first and last letter
 
 Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
 CloseConsole()

EndIf</lang> Sample output: 

night
sock
room

Python

<lang python>print "knight"[1:] # strip first character print "socks"[:-1] # strip last character print "brooms"[1:-1] # strip both first and last characters</lang>

Racket

<lang racket>

  1. lang racket

(define str "ストリング")

(substring str 1) (substring str 0 (sub1 (string-length str))) (substring str 1 (sub1 (string-length str))) </lang>

Output: 

"トリング"
"ストリン"
"トリン"

Raven

<lang Raven>define println use $s 

  $s print "\n" print

"0123456789" as $str

define offTheTop use $s 

  $s 1 0x7FFFFFFF extract

define offTheTail use $s 

  $s 0 -1 extract


$str offTheTop println $str offTheTail println $str offTheTop offTheTail println</lang>

Output:
123456789
012345678
12345678

REXX

error prone

This REXX version is error prone in that if the string is less than two characters, then the   left   and/or   substr   BIFs will fail   (because of an invalid length specified). <lang rexx>/*REXX program demonstrates removal of 1st/last/1st-and-last characters from a string.*/ @ = 'abcdefghijk' say ' the original string =' @ say 'string first character removed =' substr(@, 2) say 'string last character removed =' left(@, length(@) -1) say 'string first & last character removed =' substr(@, 2, length(@) -2) 

                                                /*stick a fork in it,  we're all done. */
  /* ╔═══════════════════════════════════════════════════════════════════════════════╗
     ║  However, the original string may be null or exactly one byte in length which ║
     ║  will cause the  BIFs to fail because of  either zero  or  a negative length. ║
     ╚═══════════════════════════════════════════════════════════════════════════════╝ */</lang>

output 

                  the original string = abcdefghijk
string first        character removed = bcdefghijk
string         last character removed = abcdefghij
string first & last character removed = bcdefghij

robust version

This REXX version correctly handles a string of zero (null) or one byte. <lang rexx>/*REXX program demonstrates removal of 1st/last/1st-and-last characters from a string.*/ @ = 'abcdefghijk' say ' the original string =' @ say 'string first character removed =' substr(@, 2) say 'string last character removed =' left(@, max(0, length(@) -1)) say 'string first & last character removed =' substr(@, 2, max(0, length(@) -2)) exit /*stick a fork in it, we're all done. */ 

                             /* [↓]  an easier to read version using a length variable.*/

@ = 'abcdefghijk' L=length(@) say ' the original string =' @ say 'string first character removed =' substr(@, 2) say 'string last character removed =' left(@, max(0, L-1) ) say 'string first & last character removed =' substr(@, 2, max(0, L-2) )</lang> output   is the same as the 1st REXX version.

faster version

This REXX version is faster   (uses   parse   instead of multiple BIFs). <lang rexx>/*REXX program demonstrates removal of 1st/last/1st-and-last characters from a string.*/ @ = 'abcdefghijk' say ' the original string =' @

parse var @ 2 z say 'string first character removed =' z

m=length(@) - 1 parse var @ z +(m) say 'string last character removed =' z

n=length(@) - 2 parse var @ 2 z +(n) if n==0 then z= /*handle special case of a length of 2.*/ say 'string first & last character removed =' z /*stick a fork in it, we're all done. */</lang> output   is the same as the 1st REXX version.

Ring

<lang ring> aString = "1Welcome to the Ring Programming Language2" see substr(aString,2,len(aString)-1) + nl + substr(aString,1,len(aString)-1) + nl + substr(aString,2,len(aString)-2) + nl </lang>

Ruby

<lang ruby>puts "knight"[1..-1] # strip first character puts "socks"[0..-2] # strip last character puts "socks".chop # alternate way to strip last character puts "brooms"[1..-2] # strip both first and last characters puts "与今令"[1..-2] # => 今</lang>

Run BASIC

<lang runbasic>s$ = "Run BASIC" print mid$(s$,2) 'strip first print left$(s$,len(s$) -1) 'strip last print mid$(s$,2,len(s$) -2) 'strip first and last</lang>

Scala

Library: Scala

<lang scala>println("knight".tail) // strip first character println("socks".init) // strip last character println("brooms".tail.init) // strip both first and last characters</lang>

Seed7

<lang seed7>$ include "seed7_05.s7i";

const proc: main is func 

 local
   const string: stri is "upraisers";
 begin
   writeln("Full string:   " <& stri);
   writeln("Without first: " <& stri[2 ..]);
   writeln("Without last:  " <& stri[.. pred(length(stri))]);
   writeln("Without both:  " <& stri[2 .. pred(length(stri))]);
 end func;</lang>

Output: 

Full string:   upraisers
Without first: praisers
Without last:  upraiser
Without both:  praiser

Sidef

Strip any characters: <lang ruby>say "knight".substr(1); # strip first character say "socks".substr(0, -1); # strip last character say "brooms".substr(1, -1); # strip both first and last characters say "与今令".substr(1, -1); # => 今</lang>

Output:
night
sock
room
今

Strip graphemes: <lang ruby>var gstr = "J\x{332}o\x{332}s\x{332}e\x{301}\x{332}"; say gstr-/^\X/; # strip first grapheme say gstr-/\X\z/; # strip last grapheme say gstr.sub(/^\X/).sub(/\X\z/); # strip both first and last graphemes</lang>

Output:
o̲s̲é̲
J̲o̲s̲
o̲s̲

Smalltalk

Works with: GNU Smalltalk

These all use built-in collection methods that will work with any kind of ordered collection, not just Strings. There is no error checking. They will fail if the string is not at least two characters long. <lang smalltalk> s := 'upraisers'. Transcript show: 'Top: ', s allButLast; nl. Transcript show: 'Tail: ', s allButFirst; nl. Transcript show: 'Without both: ', s allButFirst allButLast; nl. Transcript show: 'Without both using substring method: ', (s copyFrom: 2 to: s size - 1); nl. </lang>

Output:
Top: upraiser                                                                                                                           
Tail: praisers                                                                                                                          
Without both: praiser                                                                                                                   
Without both using substring method: praiser

SNOBOL4

<lang snobol4> "knight" len(1) rem . output  ;* strip first character 

    "socks" rtab(1) . output           ;* strip last character
    "brooms" len(1) rtab(1) . output   ;* strip both first and last characters</lang>

Standard ML

<lang sml>- val str = "abcde"; val str = "abcde" : string - String.substring(str, 1, String.size str - 1); val it = "bcde" : string - String.substring(str, 0, String.size str - 1); val it = "abcd" : string - String.substring(str, 1, String.size str - 2); val it = "bcd" : string</lang>

Swift

Swift strings are native Unicode strings and do not index through the code points. Swift's String.Index refers to true Unicode characters (Unicode grapheme clusters). Swift standard library has generic functionality that not only works with strings, but also with any type that conforms to relevant protocols. The first method presented here uses generic functions from Swift standard library:

<lang swift>let txt = "0123456789" println(dropFirst(txt)) println(dropLast(txt)) println(dropFirst(dropLast(txt)))</lang>

Output:
123456789
012345678
12345678

The other method is slicing by range subscripting: <lang swift>let txt = "0123456789" println(txt[txt.startIndex.successor() ..< txt.endIndex]) println(txt[txt.startIndex ..< txt.endIndex.predecessor()]) println(txt[txt.startIndex.successor() ..< txt.endIndex.predecessor()])</lang>

Output:
123456789
012345678
12345678

Another way is mutating the string: <lang swift>var txt = "0123456789" txt.removeAtIndex(txt.startIndex) txt.removeAtIndex(txt.endIndex.predecessor())</lang> The above functions return what they remove. You can also extend String type and define BASIC-style functions: <lang swift>extension String { 

   /// Ensure positive indexes
   
   private func positive(index: Int) -> Int {
       
       if index >= 0 { return index }
       
       return count(self) + index
   }
   
   /// Unicode character by zero-based integer (character) `index`
   /// Supports negative character index to count from end. (-1 returns character before last)
   
   subscript(index: Int) -> Character {
       
       return self[advance(startIndex, positive(index))]
   }
   
   /// String slice by character index
   
   subscript(range: Range<Int>) -> String {
       
       return self[advance(startIndex, range.startIndex) ..<
                   advance(startIndex, range.endIndex, endIndex)]
   }
   
   /// Left portion of text to `index`
   
   func left(index : Int) -> String {
       
       return self[0 ..< positive(index)]
   }
   
   /// Right portion of text from `index`
   
   func right(index : Int) -> String{
       
       return self[positive(index) ..< count(self)]
   }
   
   /// From `start` index until `end` index
   
   func mid(start: Int, _ end: Int) -> String {
       
       return self[positive(start) ..< positive(end)]
   }

}

let txt = "0123456789"

txt.right(1) // Right part without first character txt.left(-1) // Left part without last character txt.mid(1,-1) // Middle part without first and last character</lang>

Tcl

<lang tcl>puts [string range "knight" 1 end]; # strip first character puts [string range "write" 0 end-1]; # strip last character puts [string range "brooms" 1 end-1]; # strip both first and last characters</lang>

TorqueScript

String with first character removed 

 %string = "Moo";
 %string = getSubStr(%string, 1, strLen(%string) - 1);
 echo(%string);

String with last character removed 

 %string = "Moo";
 %string = getSubStr(%string, 0, strLen(%string) - 1);
 echo(%string);

String with both the first and last characters removed 

 %string = "Moo";
 %string = getSubStr(%string, 1, strLen(%string) - 2);
 echo(%string);


Output: 

 oo
 Mo
 o

TUSCRIPT

<lang tuscript> $$ MODE TUSCRIPT str="upraisers" str1=EXTRACT (str,2,0) str2=EXTRACT (str,0,-1) str3=EXTRACT (str,2,-1) PRINT str PRINT str1 PRINT str2 PRINT str3 </lang> Output: 

upraisers
praisers
upraiser
upraiser

UNIX Shell

Only zsh supports nest string manipulation.

<lang bash>

  1. !/bin/zsh

str='abcdefg' echo ${str#?} # Remove first char echo ${str%?} # Remove last char echo ${${str#?}%?} # Remove first & last chars </lang>

Vala

<lang vala> // declare test string string s = "Hello, world!"; // remove first letter string s_first = s[1:s.length]; //remove last letter string s_last = s[0:s.length - 1]; // remove first and last letters string s_first_last = s[1:s.length - 1]; </lang>

VBScript

<lang VBScript>Function TopNTail(s,mode) Select Case mode Case "top" TopNTail = Mid(s,2,Len(s)-1) Case "tail" TopNTail = Mid(s,1,Len(s)-1) Case "both" TopNTail = Mid(s,2,Len(s)-2) End Select End Function

WScript.Echo "Top: UPRAISERS = " & TopNTail("UPRAISERS","top") WScript.Echo "Tail: UPRAISERS = " & TopNTail("UPRAISERS","tail") WScript.Echo "Both: UPRAISERS = " & TopNTail("UPRAISERS","both")</lang>

Output:
Top: UPRAISERS = PRAISERS
Tail: UPRAISERS = UPRAISER
Both: UPRAISERS = PRAISER

XPL0

<lang XPL0>include c:\cxpl\stdlib; char S, P; [S:= "Smiles"; Text(0, S+1); \first character removed CrLf(0); P:= S + StrLen(S) - 2; \point to last character in string P(0):= P(0) ! $80; \set the MSb on the last character Text(0, S); \last character removed CrLf(0); Text(0, S+1); \first and last characters removed CrLf(0); ]</lang>

Output: 

miles
Smile
mile

zkl

<lang zkl>"Smiles"[1,*] //-->miles "Smiles"[0,-1] //-->Smile "Smiles"[1,-1] //-->mile</lang> [] format is [offset (zero based), length]. * means "to the end", a negative number means from the end.

ZX Spectrum Basic

<lang zxbasic>10 PRINT FN f$("knight"): REM strip the first letter. You can also write PRINT "knight"(2 TO) 20 PRINT FN l$("socks"): REM strip the last letter 30 PRINT FN b$("brooms"): REM strip both the first and last letter 100 STOP

9000 DEF FN f$(a$)=a$(2 TO LEN(a$)) 9010 DEF FN l$(a$)=a$(1 TO LEN(a$)-(1 AND (LEN(a$)>=1))) 9020 DEF FN b$(a$)=FN l$(FN f$(a$)) </lang>

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