Count occurrences of a substring: Difference between revisions
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{{task|String manipulation}}
;Task:
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
:::* the first argument being the string to search, and
:::* the second a substring to be searched for.
It should return an integer count.
<syntaxhighlight lang="pseudocode">print countSubstring("the three truths","th")
3
// do not count substrings that overlap with previously-counted substrings:
print countSubstring("ababababab","abab")
2</
The matching should yield the highest number of non-overlapping matches.
In general, this essentially means matching from left-to-right or right-to-left (see proof on talk page).
{{Template:Strings}}
<br><br>
=={{header|11l}}==
<syntaxhighlight lang="11l">print(‘the three truths’.count(‘th’))
print(‘ababababab’.count(‘abab’))</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|360 Assembly}}==
The program uses two ASSIST macros (XDECO,XPRNT) to keep the code as short as possible.
<syntaxhighlight lang="360asm">* Count occurrences of a substring 05/07/2016
COUNTSTR CSECT
USING COUNTSTR,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
STM R14,R12,12(R13) prolog
ST R13,4(R15) "
ST R15,8(R13) "
LR R13,R15 "
MVC HAYSTACK,=CL32'the three truths'
MVC LENH,=F'17' lh=17
MVC NEEDLE,=CL8'th' needle='th'
MVC LENN,=F'2' ln=2
BAL R14,SHOW call show
MVC HAYSTACK,=CL32'ababababab'
MVC LENH,=F'11' lh=11
MVC NEEDLE,=CL8'abab' needle='abab'
MVC LENN,=F'4' ln=4
BAL R14,SHOW call show
L R13,4(0,R13) epilog
LM R14,R12,12(R13) "
XR R15,R15 "
BR R14 exit
HAYSTACK DS CL32 haystack
NEEDLE DS CL8 needle
LENH DS F length(haystack)
LENN DS F length(needle)
*------- ---- show---------------------------------------------------
SHOW ST R14,SAVESHOW save return address
BAL R14,COUNT count(haystack,needle)
LR R11,R0 ic=count(haystack,needle)
MVC PG(20),HAYSTACK output haystack
MVC PG+20(5),NEEDLE output needle
XDECO R11,PG+25 output ic
XPRNT PG,80 print buffer
L R14,SAVESHOW restore return address
BR R14 return to caller
SAVESHOW DS A return address of caller
PG DC CL80' ' buffer
*------- ---- count--------------------------------------------------
COUNT ST R14,SAVECOUN save return address
SR R7,R7 n=0
LA R6,1 istart=1
L R10,LENH lh
S R10,LENN ln
LA R10,1(R10) lh-ln+1
LOOPI CR R6,R10 do istart=1 to lh-ln+1
BH ELOOPI
LA R8,NEEDLE @needle
L R9,LENN ln
LA R4,HAYSTACK-1 @haystack[0]
AR R4,R6 +istart
LR R5,R9 ln
CLCL R4,R8 if substr(haystack,istart,ln)=needle
BNE NOTEQ
LA R7,1(R7) n=n+1
A R6,LENN istart=istart+ln
NOTEQ LA R6,1(R6) istart=istart+1
B LOOPI
ELOOPI LR R0,R7 return(n)
L R14,SAVECOUN restore return address
BR R14 return to caller
SAVECOUN DS A return address of caller
* ---- -------------------------------------------------------
YREGS
END COUNTSTR</syntaxhighlight>
{{out}}
<pre>
the three truths th 3
ababababab abab 2
</pre>
=={{header|8080 Assembly}}==
The routine <code>subcnt</code> takes the string pointer in <code>HL</code>
and the substring pointer in <code>BC</code>, and returns a 16-bit count in
<code>DE</code>.
<syntaxhighlight lang="8080asm"> org 100h
jmp demo
;;; Count non-overlapping substrings (BC) in string (HL)
;;; Returns amount of matches in DE
subcnt: lxi d,0 ; Amount of matches
s_scan: mov a,m ; Get current character
ana a ; End of string?
rz ; Then stop
push b ; Keep start of substring search
push h ; Keep current location in string
s_cmp: ldax b ; Get character from substring
cmp m ; Compare to curent charracter of search string
inx b ; Advance pointers
inx h
jz s_cmp ; Keep going if they were equal
ana a ; Did we reach the end of the substring?
jz s_find ; If so, we found a match
pop h ; Otherwise, no match - restore search position
pop b ; Restore start of substring
inx h ; Try next position
jmp s_scan
s_find: inx d ; We found a match
pop b ; Discard start of the search, keep going after match
pop b ; Restore start of substring
dcx h ; The comparison routine overshoots by one
jmp s_scan
;;; Test on a few strings
demo: lxi h,pairs
loop: mov e,m ; Load string pointer
inx h
mov d,m
inx h
mov a,d ; If 0, stop
ora e
rz
mov c,m ; Load substring pointer
inx h
mov b,m
inx h
push h ; Save example pointer
xchg ; Put string pointer in HL
call subcnt ; Count substrings
mvi a,'0' ; Assuming output is <10, print output
add e ; (This is true for all examples, and a proper numeric
mov e,a ; output routine is big and not relevant.)
mvi c,2 ; CP/M character output
call 5
pop h ; Restore example pointer
jmp loop
pairs: dw str1,sub1,str2,sub2,str3,sub3,0
str1: db 'the three truths',0
sub1: db 'th',0 ; result should be 3
str2: db 'ababababab',0
sub2: db 'abab',0 ; result should be 2
str3: db 'cat',0
sub3: db 'dog',0 ; result should be 0</syntaxhighlight>
{{out}}
<pre>320</pre>
=={{header|8086 Assembly}}==
<syntaxhighlight lang="asm"> cpu 8086
org 100h
section .text
jmp demo
;;; Count non-overlapping substrings [ES:DI] in [DS:SI]
;;; Return count in AX
subcnt: xor ax,ax ; Set count to 0
xor dl,dl ; Zero to compare to
mov bp,di ; Keep copy of substring pointer
.scan: cmp dl,[si] ; End of string?
je .out ; Then we're done
mov bx,si ; Keep copy of search position
mov di,bp ; Start at beginning of substring
.cmp: xor cx,cx
dec cx
repe cmpsb ; Scan until no match
dec si ; Go to first non-match
dec di
cmp dl,[es:di] ; Reached end of substring?
je .match ; Then we found a match
mov si,bx ; If not, continue searching one
inc si ; position further
jmp .scan
.match: inc ax ; Found a match - increment count
jmp .scan
.out: ret
;;; Test the routine on a few examples
demo: mov si,pairs
.loop: lodsw ; Load string pointer
test ax,ax ; If 0, stop
jz .out
xchg dx,ax
lodsw ; Load substring pointer
xchg di,ax
push si ; Keep example pointer
xchg si,dx
call subcnt ; Count substrings
call prax ; Print amount of substrings
pop si ; Restore example pointer
jmp .loop
.out: ret
;;; Print AX as number
prax: mov bx,num ; Pointer to end of number string
mov cx,10 ; Divisor
.dgt: xor dx,dx ; Divide by 10
div cx
add dl,'0' ; Add ASCII 0 to remainder
dec bx ; Store digit
mov [bx],dl
test ax,ax ; If number not zero yet
jnz .dgt ; Find rest of digits
mov dx,bx ; Print number string
mov ah,9
int 21h
ret
section .data
db '*****' ; Output number placeholder
num: db ' $'
;;; Examples
pairs: dw .str1,.sub1,.str2,.sub2,.str3,.sub3,0
.str1: db 'the three truths',0
.sub1: db 'th',0 ; result should be 3
.str2: db 'ababababab',0
.sub2: db 'abab',0 ; result should be 2
.str3: db 'cat',0
.sub3: db 'dog',0 ; result should be 0</syntaxhighlight>
{{out}}
<pre>3 2 0</pre>
=={{header|AArch64 Assembly}}==
{{works with|as|Raspberry Pi 3B version Buster 64 bits <br> or android 64 bits with application Termux }}
<syntaxhighlight lang AArch64 Assembly>
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program strcptsub64.s */
/************************************/
/* Constantes */
/************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"
/************************************/
/* Initialized data */
/************************************/
.data
szMessResult: .asciz "Result: "
szString: .asciz "the three truths"
szSubString: .asciz "th"
szString1: .asciz "ababababab"
szSubString1: .asciz "abab"
szCarriageReturn: .asciz "\n"
szMessStart: .asciz "Program 64 bits start.\n"
/************************************/
/* UnInitialized data */
/************************************/
.bss
sZoneConv: .skip 24
/************************************/
/* code section */
/************************************/
.text
.global main
main: // entry of program
ldr x0,qAdrszMessStart
bl affichageMess
ldr x0,qAdrszString
ldr x1,qAdrszSubString
bl countSubString
ldr x0,qAdrszString1
ldr x1,qAdrszSubString1
bl countSubString
100: // standard end of the program
mov x0, #0 // return code
mov x8, #EXIT // request to exit program
svc 0 // perform the system call
qAdrszString: .quad szString
qAdrszSubString: .quad szSubString
qAdrszString1: .quad szString1
qAdrszSubString1: .quad szSubString1
qAdrsZoneConv: .quad sZoneConv
qAdrszMessResult: .quad szMessResult
qAdrszCarriageReturn: .quad szCarriageReturn
qAdrszMessStart: .quad szMessStart
/***************************************************/
/* count sub string of string */
/***************************************************/
/* r0 contains a string */
/* r1 contains a substring */
/* r0 return substring count */
countSubString:
stp x1,lr,[sp,-16]!
stp x2,x3,[sp,-16]!
stp x4,x5,[sp,-16]!
stp x6,x7,[sp,-16]!
mov x4,#0 // counter
mov x3,#0 // index string
mov x5,#0 // index substring
1:
ldrb w6,[x0,x5] // load byte of string
ldrb w7,[x1,x3] // load byte of substring
cmp x6,x7 // compare byte
bne 2f // not equal
cmp x6,#0 // string end ?
beq 3f // yes
add x5,x5,#1 // else increment index
add x3,x3,#1
b 1b // and loop
2: // characters not equal
cmp x6,#0 // end string ?
beq 4f
cmp x7,#0 // end substring ?
add x6,x4,1
csel x4,x6,x4,eq // yes -> increment counter
mov x3,#0 // raz index substring
add x5,x5,#1 // increment string index
b 1b // and loop
3: // end string and end substring
add x4,x4,#1 // increment counter
4: // result display
mov x0,x4
ldr x1,qAdrsZoneConv
bl conversion10
ldr x0,qAdrszMessResult
bl affichageMess
ldr x0,qAdrsZoneConv
bl affichageMess
ldr x0,qAdrszCarriageReturn
bl affichageMess
mov x0,x4
100:
ldp x6,x7,[sp],16
ldp x4,x5,[sp],16
ldp x2,x3,[sp],16
ldp x1,lr,[sp],16
ret
/***************************************************/
/* ROUTINES INCLUDE */
/***************************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeARM64.inc"
</syntaxhighlight>
{{Out}}
<pre>
Program 64 bits start.
Result: 3
Result: 2
</pre>
=={{header|Action!}}==
<syntaxhighlight lang="action!">BYTE FUNC CountSubstring(CHAR ARRAY s,sub)
BYTE i,j,res,found
i=1 res=0
WHILE i-1+sub(0)<=s(0)
DO
found=1
FOR j=1 TO sub(0)
DO
IF s(j+i-1)#sub(j) THEN
found=0
EXIT
FI
OD
IF found=1 THEN
i==+sub(0)
res==+1
ELSE
i==+1
FI
OD
RETURN (res)
PROC Test(CHAR ARRAY s,sub)
BYTE c
c=CountSubstring(s,sub)
PrintF("%B ""%S"" in ""%S""%E",c,sub,s)
RETURN
PROC Main()
Test("the three truths","th")
Test("ababababab","abab")
Test("11111111","11")
Test("abcdefg","123")
RETURN</syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Count_occurrences_of_a_substring.png Screenshot from Atari 8-bit computer]
<pre>
3 "th" in "the three truths"
2 "abab" in "ababababab"
4 "11" in "11111111"
0 "123" in "abcdefg"
</pre>
=={{header|Ada}}==
<syntaxhighlight lang="ada">with Ada.Strings.Fixed, Ada.Integer_Text_IO;
procedure Substrings is
begin
Ada.Integer_Text_IO.Put (Ada.Strings.Fixed.Count (Source => "the three truths",
Pattern => "th"));
Ada.Integer_Text_IO.Put (Ada.Strings.Fixed.Count (Source => "ababababab",
Pattern => "abab"));
end Substrings;</syntaxhighlight>
{{out}}
<pre> 3 2</pre>
=={{header|ALGOL 68}}==
Algol68 has no build in function to do this task, hence the need to create a ''count string in string'' routine.<br/>
If your Algol 68 compiler/interpreter does not have ''string in string'', there is an implementation on Rosetta Code [[ALGOL_68/prelude#string_in_string|here]].<br>
<syntaxhighlight lang="algol68">PROC count string in string = (STRING needle, haystack)INT: (
INT start:=LWB haystack, next, out:=0;
FOR count WHILE string in string(needle, next, haystack[start:]) DO
Line 27 ⟶ 441:
);
print((
whole( count string in string("th", "the three truths"), 0 ) # expect 3 #, " ",
whole( count string in string("abab", "ababababab"), 0 ) # expect 2 #, " ",
whole( count string in string("a*b", "abaabba*bbaba*bbab"), 0 ) # expect 2 #, newline
))
</syntaxhighlight>
{{out}}
<pre>
3 2 2
</pre>
=={{header|Apex}}==
Apex example for 'Count occurrences of a substring'.
<syntaxhighlight lang="apex">
String substr = 'ABC';
String str = 'ABCZZZABCYABCABCXXABC';
Integer substrLen = substr.length();
Integer count = 0;
Integer index = str.indexOf(substr);
while (index >= 0) {
count++;
str = str.substring(index+substrLen);
index = str.indexOf(substr);
}
System.debug('Count String : '+count);
</syntaxhighlight>
<pre>
Count String : 5
</pre>
=={{header|APL}}==
{{works with|Dyalog APL}}
<syntaxhighlight lang="apl">csubs←{0=x←⊃⍸⍺⍷⍵:0 ⋄ 1+⍺∇(¯1+x+⍴⍺)↓⍵}</syntaxhighlight>
{{out}}
<pre> 'th' 'abab' 'dog' csubs¨ 'the three truths' 'ababababab' 'cat'
3 2 0</pre>
=={{header|AppleScript}}==
This is a good example of the kind of problem to which standard libraries (a regex library in this case) would offer most languages a simple and immediate solution.
AppleScript, however, for want of various basics like regex and math library functions, can require scripters to draw on the supplementary resources of Bash, using the built-in ''do shell script'' function.
A slightly faster approach to seeking outside library help has, however, become possible since OS X 10.10 added JavaScript as an osalang sibling for AppleScript. Rather than using the resources of Bash, we can more quickly use AppleScript's built in ObjC interface to pass a subproblem over to the more richly endowed JavaScript core of JavaScript for Automation.
Here we use a generic ''evalOSA(language, code)'' function to apply a JavaScript for Automation regex to a pair of AppleScript strings, using OSAKit.
<syntaxhighlight lang="applescript">use framework "OSAKit"
on run
{countSubstring("the three truths", "th"), ¬
countSubstring("ababababab", "abab")}
end run
on countSubstring(str, subStr)
return evalOSA("JavaScript", "var matches = '" & str & "'" & ¬
".match(new RegExp('" & subStr & "', 'g'));" & ¬
"matches ? matches.length : 0") as integer
end countSubstring
-- evalOSA :: ("JavaScript" | "AppleScript") -> String -> String
on evalOSA(strLang, strCode)
set ca to current application
set oScript to ca's OSAScript's alloc's initWithSource:strCode ¬
|language|:(ca's OSALanguage's languageForName:(strLang))
set {blnCompiled, oError} to oScript's compileAndReturnError:(reference)
if blnCompiled then
set {oDesc, oError} to oScript's executeAndReturnError:(reference)
if (oError is missing value) then return oDesc's stringValue as text
end if
return oError's NSLocalizedDescription as text
end evalOSA</syntaxhighlight>
{{out}}
<pre>
{3, 2}
</pre>
----
The above assertions notwithstanding, it's always been possible to use AppleScript's text item delimiters for this purpose with its native strings, except that the TIDs have only observed the current considering/ignoring state with the 'unicode text' class, which was introduced around Mac OS X 10.4 and became AppleScript's only native text class with the introduction of AppleScript 2.0 in Mac OS X 10.5.
<syntaxhighlight lang="applescript">on countSubstring(theString, theSubstring)
set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to theSubstring
set substringCount to (count theString's text items) - 1
set AppleScript's text item delimiters to astid
return substringCount
end countSubstring
{countSubstring("the three truths", "th"), countSubstring("ababababab", "abab")}</syntaxhighlight>
{{Out}}
<syntaxhighlight lang="applescript">{3, 2}</syntaxhighlight>
=={{header|ARM Assembly}}==
{{works with|as|Raspberry Pi <br> or android 32 bits with application Termux}}
<syntaxhighlight lang ARM Assembly>
/* ARM assembly Raspberry PI */
/* program strcptsub.s */
/************************************/
/* Constantes */
/************************************/
/* for this file see task include a file in language ARM assembly*/
.include "../constantes.inc"
/************************************/
/* Initialized data */
/************************************/
.data
szMessResult: .asciz "Result: "
szString: .asciz "the three truths"
szSubString: .asciz "th"
szString1: .asciz "ababababab"
szSubString1: .asciz "abab"
szCarriageReturn: .asciz "\n"
szMessStart: .asciz "Program 32 bits start.\n"
/************************************/
/* UnInitialized data */
/************************************/
.bss
sZoneConv: .skip 24
/************************************/
/* code section */
/************************************/
.text
.global main
main: @ entry of program
ldr r0,iAdrszMessStart
bl affichageMess
ldr r0,iAdrszString
ldr r1,iAdrszSubString
bl countSubString
ldr r0,iAdrszString1
ldr r1,iAdrszSubString1
bl countSubString
100: @ standard end of the program
mov r0, #0 @ return code
mov r7, #EXIT @ request to exit program
svc 0 @ perform the system call
iAdrszString: .int szString
iAdrszSubString: .int szSubString
iAdrszString1: .int szString1
iAdrszSubString1: .int szSubString1
iAdrsZoneConv: .int sZoneConv
iAdrszMessResult: .int szMessResult
iAdrszCarriageReturn: .int szCarriageReturn
iAdrszMessStart: .int szMessStart
/***************************************************/
/* count sub string of string */
/***************************************************/
/* r0 contains a string */
/* r1 contains a substring */
/* r0 return substring count */
countSubString:
push {r1-r7,lr} @ save registers
mov r4,#0 @ counter
mov r3,#0 @ index string
Mov r5,#0 @ index substring
1:
ldrb r6,[r0,r5] @ load byte of string
ldrb r7,[r1,r3] @ load byte of substring
cmp r6,r7 @ compare byte
bne 2f @ not equal
cmp r6,#0 @ string end ?
beq 3f @ yes
add r5,r5,#1 @ else increment index
add r3,r3,#1
b 1b @ and loop
2: @ characters not equal
cmp r6,#0 @ end string ?
beq 4f
cmp r7,#0 @ end substring ?
addeq r4,r4,#1 @ yes -> increment counter
mov r3,#0 @ raz index substring
add r5,r5,#1 @ increment string index
b 1b @ and loop
3: @ end string and end substring
add r4,r4,#1 @ increment counter
4: @ result display
mov r0,r4
ldr r1,iAdrsZoneConv
bl conversion10
ldr r0,iAdrszMessResult
bl affichageMess
ldr r0,iAdrsZoneConv
bl affichageMess
ldr r0,iAdrszCarriageReturn
bl affichageMess
mov r0,r4
100:
pop {r1-r7,pc}
/***************************************************/
/* ROUTINES INCLUDE */
/***************************************************/
/* for this file see task include a file in language ARM assembly*/
.include "../affichage.inc"
</syntaxhighlight>
{{Out}}
<pre>
Program 32 bits start.
Result: 3
Result: 2
</pre>
=={{header|Arturo}}==
<syntaxhighlight lang="rebol">countOccurrences: function [str, substr]-> size match str substr
loop [["the three truths" "th"] ["ababababab" "abab"]] 'pair ->
print [
~"occurrences of '|last pair|' in '|first pair|':"
countOccurrences first pair last pair
]</syntaxhighlight>
{{out}}
<pre>occurrences of 'th' in 'the three truths': 3
occurrences of 'abab' in 'ababababab': 2</pre>
=={{header|AutoHotkey}}==
While it is simple enough to parse the string,
AutoHotkey has a rather unconventional method which outperforms this.
StringReplace sets the number of replaced strings to ErrorLevel.
<syntaxhighlight lang="autohotkey">MsgBox % countSubstring("the three truths","th") ; 3
MsgBox % countSubstring("ababababab","abab") ; 2
CountSubstring(fullstring, substring){
StringReplace, junk, fullstring, %substring%, , UseErrorLevel
return errorlevel
}</syntaxhighlight>
=={{header|AWK}}==
<syntaxhighlight lang="awk">#
# countsubstring(string, pattern)
# Returns number of occurrences of pattern in string
# Pattern treated as a literal string (regex characters not expanded)
#
function countsubstring(str, pat, len, i, c) {
c = 0
if( ! (len = length(pat) ) )
return 0
while(i = index(str, pat)) {
str = substr(str, i + len)
c++
}
return c
}
#
# countsubstring_regex(string, regex_pattern)
# Returns number of occurrences of pattern in string
# Pattern treated as regex
#
function countsubstring_regex(str, pat, c) {
c = 0
c += gsub(pat, "", str)
return c
}
BEGIN {
print countsubstring("[do&d~run?d!run&>run&]", "run&")
print countsubstring_regex("[do&d~run?d!run&>run&]", "run[&]")
print countsubstring("the three truths","th")
}</syntaxhighlight>
{{out}}
<pre>$ awk -f countsubstring.awk
2
2
3
</pre>
=={{header|BaCon}}==
<syntaxhighlight lang="qbasic">FUNCTION Uniq_Tally(text$, part$)
LOCAL x
WHILE TALLY(text$, part$)
INCR x
text$ = MID$(text$, INSTR(text$, part$)+LEN(part$))
WEND
RETURN x
END FUNCTION
PRINT "the three truths - th: ", Uniq_Tally("the three truths", "th")
PRINT "ababababab - abab: ", Uniq_Tally("ababababab", "abab")</syntaxhighlight>
{{out}}
<pre>
the three truths - th: 3
ababababab - abab: 2
</pre>
=={{header|BASIC}}==
{{works with|QBasic}}
In FreeBASIC, this needs to be compiled with <code>-lang qb</code> or <code>-lang fblite</code>.
<syntaxhighlight lang="qbasic">DECLARE FUNCTION countSubstring& (where AS STRING, what AS STRING)
PRINT "the three truths, th:", countSubstring&("the three truths", "th")
PRINT "ababababab, abab:", countSubstring&("ababababab", "abab")
FUNCTION countSubstring& (where AS STRING, what AS STRING)
DIM c AS LONG, s AS LONG
s = 1 - LEN(what)
DO
s = INSTR(s + LEN(what), where, what)
IF 0 = s THEN EXIT DO
c = c + 1
LOOP
countSubstring = c
END FUNCTION</syntaxhighlight>
{{out}}
the three truths, th: 3
ababababab, abab: 2
See also: [[#Liberty BASIC|Liberty BASIC]], [[#PowerBASIC|PowerBASIC]], [[#PureBasic|PureBasic]].
==={{header|Applesoft BASIC}}===
<syntaxhighlight lang="applesoftbasic">10 F$ = "TH"
20 S$ = "THE THREE TRUTHS"
30 GOSUB 100"COUNT SUBSTRING
40 PRINT R
50 F$ = "ABAB"
60 S$ = "ABABABABAB"
70 GOSUB 100"COUNT SUBSTRING
80 PRINT R
90 END
100 R = 0
110 F = LEN(F$)
120 S = LEN(S$)
130 IF F > S THEN RETURN
140 IF F = 0 THEN RETURN
150 IF F = S AND F$ = S$ THEN R = 1 : RETURN
160 FOR I = 1 TO S - F
170 IF F$ = MID$(S$, I, F) THEN R = R + 1 : I = I + F - 1
180 NEXT I
190 RETURN</syntaxhighlight>
==={{header|BASIC256}}===
{{trans|Run BASIC}}
<syntaxhighlight lang="freebasic">print countSubstring("the three truths","th")
print countSubstring("ababababab","abab")
end
function countSubstring(s$,find$)
i = 1
while instr(s$,find$,i) <> 0
countSubstring += 1
i = instr(s$,find$,i) + length(find$)
end while
end function</syntaxhighlight>
{{out}}
<pre>Igual que la entrada de Run BASIC.</pre>
==={{header|Chipmunk Basic}}===
{{works with|Chipmunk Basic|3.6.4}}
{{works with|Applesoft BASIC}}
{{works with|MSX_BASIC}}
{{works with|PC-BASIC|any}}
{{works with|QBasic}}
{{trans|Applesoft BASIC}}
<syntaxhighlight lang="qbasic">10 CLS : REM 10 HOME for Applesoft BASIC
20 F$ = "TH"
30 S$ = "THE THREE TRUTHS"
40 GOSUB 110: REM COUNT SUBSTRING
50 PRINT R
60 F$ = "ABAB"
70 S$ = "ABABABABAB"
80 GOSUB 110: REM COUNT SUBSTRING
90 PRINT R
100 END
110 R = 0
120 F = LEN(F$)
130 S = LEN(S$)
140 IF F > S THEN RETURN
150 IF F = 0 THEN RETURN
160 IF F = S AND F$ = S$ THEN R = 1: RETURN
170 FOR I = 1 TO S - F
180 IF F$ = MID$(S$, I, F) THEN R = R + 1: I = I + F - 1
190 NEXT I
200 RETURN</syntaxhighlight>
==={{header|GW-BASIC}}===
The [[#Chipmunk_Basic|Chipmunk Basic]] solution works without any changes.
==={{header|IS-BASIC}}===
<syntaxhighlight lang="is-basic">100 INPUT PROMPT "String: ":TXT$
110 INPUT PROMPT "Substring: ":SUB$
120 PRINT COUNT(LCASE$(TXT$),LCASE$(SUB$))
130 DEF COUNT(TXT$,SUB$)
140 LET N=0:LET PO=1
150 DO
160 LET PO=POS(TXT$,SUB$,PO)
170 IF PO THEN LET N=N+1:LET PO=PO+LEN(SUB$)
180 LOOP UNTIL PO=0
190 LET COUNT=N
200 END DEF</syntaxhighlight>
==={{header|MSX Basic}}===
The [[#Chipmunk_Basic|Chipmunk Basic]] solution works without any changes.
==={{header|Sinclair ZX81 BASIC}}===
Works with 1k of RAM.
<syntaxhighlight lang="basic"> 10 LET S$="THE THREE TRUTHS"
20 LET U$="TH"
30 GOSUB 100
40 PRINT N
50 LET S$="ABABABABAB"
60 LET U$="ABAB"
70 GOSUB 100
80 PRINT N
90 STOP
100 LET N=0
110 LET I=0
120 LET I=I+1
130 IF I+LEN U$>LEN S$ THEN RETURN
140 IF S$(I TO I+LEN U$-1)<>U$ THEN GOTO 120
150 LET N=N+1
160 LET I=I+LEN U$
170 GOTO 130</syntaxhighlight>
==={{header|True BASIC}}===
{{trans|QBasic}}
<syntaxhighlight lang="qbasic">FUNCTION countsubstring(where$, what$)
LET c = 0
LET s = 1-LEN(what$)
DO
LET s = POS(where$,what$,s+LEN(what$))
IF 0 = s THEN EXIT DO
LET c = c+1
LOOP
LET countsubstring = c
END FUNCTION
PRINT "the three truths, th:", countSubstring("the three truths", "th")
PRINT "ababababab, abab:", countSubstring("ababababab", "abab")
END</syntaxhighlight>
==={{header|Yabasic}}===
{{trans|Run BASIC}}
<syntaxhighlight lang="yabasic">print countSubstring("the three truths","th")
print countSubstring("ababababab","abab")
end
sub countSubstring(s$,find$)
countSubstring = 0
i = 1
while instr(s$,find$,i) <> 0
countSubstring = countSubstring + 1
i = instr(s$,find$,i) + len(find$)
end while
return countSubstring
end sub</syntaxhighlight>
{{out}}
<pre>Igual que la entrada de Run BASIC.</pre>
=={{header|Batch File}}==
<syntaxhighlight lang="dos">@echo off
setlocal enabledelayedexpansion
::Main
call :countString "the three truths","th"
call :countString "ababababab","abab"
pause>nul
exit /b
::/Main
::Procedure
:countString
set input=%~1
set cnt=0
:count_loop
set trimmed=!input:*%~2=!
if "!trimmed!"=="!input!" (echo.!cnt!&goto :EOF)
set input=!trimmed!
set /a cnt+=1
goto count_loop</syntaxhighlight>
{{Out}}
<pre>3
2</pre>
=={{header|BBC BASIC}}==
<syntaxhighlight lang="bbcbasic"> tst$ = "the three truths"
sub$ = "th"
PRINT ; FNcountSubstring(tst$, sub$) " """ sub$ """ in """ tst$ """"
tst$ = "ababababab"
sub$ = "abab"
PRINT ; FNcountSubstring(tst$, sub$) " """ sub$ """ in """ tst$ """"
END
DEF FNcountSubstring(A$, B$)
LOCAL I%, N%
I% = 1 : N% = 0
REPEAT
I% = INSTR(A$, B$, I%)
IF I% THEN N% += 1 : I% += LEN(B$)
UNTIL I% = 0
= N%
</syntaxhighlight>
{{out}}
<pre>3 "th" in "the three truths"
2 "abab" in "ababababab"</pre>
=={{header|BCPL}}==
<syntaxhighlight lang="bcpl">get "libhdr"
let countsubstr(str, match) = valof
$( let i, count = 1, 0
while i <= str%0 do
test valof
$( for j = 1 to match%0
unless match%j = str%(i+j-1)
resultis false
resultis true
$)
then
$( count := count + 1
i := i + match%0
$)
else
i := i + 1
resultis count
$)
let show(str, match) be
writef("*"%S*" in *"%S*": %N*N",
match, str, countsubstr(str, match))
let start() be
$( show("the three truths", "th")
show("ababababab", "abab")
show("cat", "dog")
$)</syntaxhighlight>
{{out}}
<pre>"th" in "the three truths": 3
"abab" in "ababababab": 2
"dog" in "cat": 0</pre>
=={{header|BQN}}==
<code>/𝕨⍷𝕩</code> finds locations of substrings, rest of the function suppresses overlapping substrings.
<syntaxhighlight lang="bqn">Find←{i←/𝕨⍷𝕩, i/˜i≥»0≤◶⟨⊣,(≠𝕨)+⊢⟩`i}
•Show "abab" Find "ababababab"
•Show "th" Find "the three truths"</syntaxhighlight>
<syntaxhighlight lang="text">2
3</syntaxhighlight>
Using strings.bqn from bqn-libs, another solution is <code>Find←+´Locate</code>, since <code>Locate</code> performs a non-overlapping search.
=={{header|Bracmat}}==
<syntaxhighlight lang="bracmat"> ( count-substring
= n S s p
. 0:?n:?p
& !arg:(?S.?s)
& @( !S
: ?
( [!p ? !s [?p ?
& !n+1:?n
& ~
)
)
| !n
)
& out$(count-substring$("the three truths".th))
& out$(count-substring$(ababababab.abab))
& ;</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|C}}==
<
#include <string.h>
Line 59 ⟶ 1,041:
printf("not: %d\n", match("abababababa", "aba", 0));
return 0;
}</
Alternate version:
<syntaxhighlight lang="c">#include <stdio.h>
#include <string.h>
// returns count of non-overlapping occurrences of 'sub' in 'str'
int countSubstring(const char *str, const char *sub)
{
int length = strlen(sub);
if (length == 0) return 0;
int count = 0;
for (str = strstr(str, sub); str; str = strstr(str + length, sub))
++count;
return count;
}
int main()
{
printf("%d\n", countSubstring("the three truths", "th"));
printf("%d\n", countSubstring("ababababab", "abab"));
printf("%d\n", countSubstring("abaabba*bbaba*bbab", "a*b"));
return 0;
}</syntaxhighlight>
{{out}}
<pre>
3
2
2
</pre>
=={{header|C sharp|C#}}==
<syntaxhighlight lang="c sharp">using System;
class SubStringTestClass
{
public static int CountSubStrings(this string testString, string testSubstring)
{
int count = 0;
if (testString.Contains(testSubstring))
{
for (int i = 0; i < testString.Length; i++)
{
if (testString.Substring(i).Length >= testSubstring.Length)
{
bool equals = testString.Substring(i, testSubstring.Length).Equals(testSubstring);
if (equals)
{
count++;
i += testSubstring.Length - 1; // Fix: Don't count overlapping matches
}
}
}
}
return count;
}
}</syntaxhighlight>
Using C# 6.0's expression-bodied member, null-conditional operator, and coalesce operator features:
<syntaxhighlight lang="c sharp">using System;
class SubStringTestClass
{
public static int CountSubStrings(this string testString, string testSubstring) =>
testString?.Split(new [] { testSubstring }, StringSplitOptions.None)?.Length - 1 ?? 0;
}</syntaxhighlight>
=={{header|C++}}==
<
#include <string>
Line 70 ⟶ 1,119:
if (sub.length() == 0) return 0;
int count = 0;
for (size_t offset =
{
++count;
Line 84 ⟶ 1,132:
std::cout << countSubstring("ababababab", "abab") << '\n';
std::cout << countSubstring("abaabba*bbaba*bbab", "a*b") << '\n';
return 0;
}</syntaxhighlight>
{{out}}
<pre>
3
Line 91 ⟶ 1,141:
2
</pre>
=={{header|Clojure}}==
Use a sequence of regexp matches to count occurrences.
<syntaxhighlight lang="clojure">
(defn re-quote
"Produces a string that can be used to create a Pattern
that would match the string text as if it were a literal pattern.
Metacharacters or escape sequences in text will be given no special
meaning"
[text]
(java.util.regex.Pattern/quote text))
(defn count-substring [txt sub]
(count (re-seq (re-pattern (re-quote sub)) txt)))
</syntaxhighlight>
Use the trick of blank replacement and maths to count occurrences.
<syntaxhighlight lang="clojure">
(defn count-substring1 [txt sub]
(/ (- (count txt) (count (.replaceAll txt sub "")))
(count sub)))
</syntaxhighlight>
A Java 8 stream-based solution, which should avoid creation of temporary strings
(though it will produce temporary MatchResult instances).
<syntaxhighlight lang="clojure">
(defn count-substring2 [txt sub]
(-> sub
(re-quote)
(re-pattern)
(re-matcher txt)
(.results)
(.count)))
</syntaxhighlight>
=={{header|COBOL}}==
<code>INSPECT</code> can be used for this task without having to create a function.
<syntaxhighlight lang="cobol"> IDENTIFICATION DIVISION.
PROGRAM-ID. testing.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 occurrences PIC 99.
PROCEDURE DIVISION.
INSPECT "the three truths" TALLYING occurrences FOR ALL "th"
DISPLAY occurrences
MOVE 0 TO occurrences
INSPECT "ababababab" TALLYING occurrences FOR ALL "abab"
DISPLAY occurrences
MOVE 0 TO occurrences
INSPECT "abaabba*bbaba*bbab" TALLYING occurrences
FOR ALL "a*b"
DISPLAY occurrences
GOBACK
.</syntaxhighlight>
{{out}}
<pre>
03
02
02
</pre>
=={{header|CoffeeScript}}==
<syntaxhighlight lang="coffeescript">
countSubstring = (str, substr) ->
n = 0
i = 0
while (pos = str.indexOf(substr, i)) != -1
n += 1
i = pos + substr.length
n
console.log countSubstring "the three truths", "th"
console.log countSubstring "ababababab", "abab"
</syntaxhighlight>
=={{header|Common Lisp}}==
<syntaxhighlight lang="lisp">(defun count-sub (str pat)
(loop with z = 0 with s = 0 while s do
(when (setf s (search pat str :start2 s))
(incf z) (incf s (length pat)))
finally (return z)))
(count-sub "ababa" "ab") ; 2
(count-sub "ababa" "aba") ; 1</syntaxhighlight>
=={{header|Cowgol}}==
<syntaxhighlight lang="cowgol">include "cowgol.coh";
sub countSubstring(str: [uint8], match: [uint8]): (count: uint8) is
count := 0;
while [str] != 0 loop
var find := match;
var loc := str;
while [loc] == [find] loop
find := @next find;
loc := @next loc;
end loop;
if [find] == 0 then
str := loc;
count := count + 1;
else
str := @next str;
end if;
end loop;
end sub;
print_i8(countSubstring("the three truths","th")); # should print 3
print_nl();
print_i8(countSubstring("ababababab","abab")); # should print 2
print_nl();
print_i8(countSubstring("cat","dog")); # should print 0
print_nl();</syntaxhighlight>
{{out}}
<pre>3
2
0</pre>
=={{header|D}}==
<syntaxhighlight lang="d">void main() {
import std.stdio, std.algorithm;
"the three truths".count("th").writeln;
}</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|
<syntaxhighlight lang="delphi">program OccurrencesOfASubstring;
{$APPTYPE CONSOLE}
uses StrUtils;
function CountSubstring(const aString, aSubstring: string): Integer;
var
lPosition: Integer;
begin
Result
lPosition := PosEx(aSubstring, aString);
while lPosition <> 0 do
begin
Inc(Result);
lPosition := PosEx(aSubstring, aString, lPosition + Length(aSubstring));
end;
end;
begin
Writeln(CountSubstring('the three truths', 'th'));
Writeln(CountSubstring('ababababab', 'abab'));
end.</syntaxhighlight>
=={{header|
<syntaxhighlight lang="draco">proc countSubstring(*char string, substring) word:
word count;
*char pos, loc;
count := 0;
while string* /= '\e' do
pos := substring;
loc := string;
while loc* = pos* do
loc := loc + 1;
pos := pos + 1
od;
if pos* = '\e' then
string := loc;
count := count + 1
else
string := string + 1
fi
od;
count
corp
proc main() void:
writeln(countSubstring("the three truths", "th"));
writeln(countSubstring("ababababab", "abab"))
corp</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Dyalect}}==
<syntaxhighlight lang="dyalect">func countSubstring(str, val) {
var idx = 0
var count = 0
while true {
idx = str.IndexOf(val, idx)
if idx == -1 {
break
}
idx += val.Length()
count += 1
}
return count
}
print(countSubstring("the three truths", "th"))
print(countSubstring("ababababab", "abab"))</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Déjà Vu}}==
<syntaxhighlight lang="dejavu">!. count "the three truths" "th"
!. count "ababababab" "abab"</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|EasyLang}}==
<syntaxhighlight lang="easylang">
func count str$ pat$ .
ind = 1
while ind + len pat$ - 1 <= len str$
if substr str$ ind len pat$ = pat$
cnt += 1
ind += len pat$
else
ind += 1
.
.
return cnt
.
print count "the three truths" "th"
print count "ababababab" "abab"
print count "11111111" "11"
print count "11111111" "12"
print count "12" "12"
</syntaxhighlight>
=={{header|EchoLisp}}==
<syntaxhighlight lang="scheme">
;; from Racket
(define count-substring
(compose length regexp-match*))
(count-substring "aab" "graabaabdfaabgh") ;; substring
→ 3
(count-substring "/ .e/" "Longtemps je me suis couché de bonne heure") ;; regexp
→ 4
</syntaxhighlight>
=={{header|EGL}}==
{{works with|EDT}}
The "remove and count the difference" and "manual loop" methods. Implementation includes protection from empty source and search strings.
<syntaxhighlight lang="egl">program CountStrings
function main()
SysLib.writeStdout("Remove and Count:");
SysLib.writeStdout(countSubstring("th", "the three truths"));
SysLib.writeStdout(countSubstring("abab", "ababababab"));
SysLib.writeStdout(countSubstring("a*b", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstring("a", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstring(" ", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstring("", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstring("a", ""));
SysLib.writeStdout(countSubstring("", ""));
SysLib.writeStdout("Manual Loop:");
SysLib.writeStdout(countSubstringWithLoop("th", "the three truths"));
SysLib.writeStdout(countSubstringWithLoop("abab", "ababababab"));
SysLib.writeStdout(countSubstringWithLoop("a*b", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstringWithLoop("a", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstringWithLoop(" ", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstringWithLoop("", "abaabba*bbaba*bbab"));
SysLib.writeStdout(countSubstringWithLoop("a", ""));
SysLib.writeStdout(countSubstringWithLoop("", ""));
end
function countSubstring(substr string in, str string in) returns(int)
if(str.length() > 0 and substr.length() > 0)
return (str.length() - str.replaceStr(subStr, "").length()) / subStr.length();
else
return 0;
end
end
function countSubstringWithLoop(substr string in, str string in) returns(int)
count int = 0;
loc, index int = 1;
strlen int = str.length();
substrlen int = substr.length();
if(strlen > 0 and substrlen > 0)
while(loc != 0 and index <= strlen)
loc = str.indexOf(substr, index);
if(loc > 0)
count += 1;
index = loc + substrlen;
end
end
end
return count;
end
end
</syntaxhighlight>
{{out}}
<pre>Remove and Count:
3
2
2
7
0
0
0
0
Manual Loop:
3
2
2
7
0
0
0
0</pre>
=={{header|Eiffel}}==
<syntaxhighlight lang="eiffel">
class
APPLICATION
inherit
ARGUMENTS
create
make
feature {NONE} -- Initialization
make
-- Run application.
do
occurance := 0
from
index := 1
until
index > text.count
loop
temp := text.fuzzy_index(search_for, index, 0)
if
temp /= 0
then
index := temp + search_for.count
occurance := occurance + 1
else
index := text.count + 1
end
end
print(occurance)
end
index:INTEGER
temp:INTEGER
occurance:INTEGER
text:STRING = "ababababab"
search_for:STRING = "abab"
end
</syntaxhighlight>
=={{header|Elixir}}==
<syntaxhighlight lang="elixir">countSubstring = fn(_, "") -> 0
(str, sub) -> length(String.split(str, sub)) - 1 end
data = [ {"the three truths", "th"},
{"ababababab", "abab"},
{"abaabba*bbaba*bbab", "a*b"},
{"abaabba*bbaba*bbab", "a"},
{"abaabba*bbaba*bbab", " "},
{"abaabba*bbaba*bbab", ""},
{"", "a"},
{"", ""} ]
Enum.each(data, fn{str, sub} ->
IO.puts countSubstring.(str, sub)
end)</syntaxhighlight>
{{out}}
<pre>
3
2
2
7
0
0
0
0
</pre>
=={{header|Emacs Lisp}}==
Two Emacs Lisp solutions are shown below
<syntaxhighlight lang="lisp">
;; version 1, which takes advantage of the how-many function,
;; which runs only in a buffer
(defun count-substrings (text substring)
"Count non-overlapping occurrences of SUBSTRING in TEXT."
(with-temp-buffer ; create a temporary buffer, which will be deleted when function finishes
(insert text) ; insert TEXT into the empty buffer
(goto-char (point-min)) ; go to the beginning of the buffer
(how-many substring))) ; count how many occurrences of SUBSTRING
;; version 2, which operates on a string
(defun count-substrings (text substring)
"Count non-overlapping occurences of SUBSTRING in TEXT."
(let ((substrings)) ; empty list to add occurrences of SUBSTRING as we find them
(while (string-match substring text) ; as long as we can find SUBSTRING in TEXT
(push (match-string 0 text) substrings) ; add the SUBSTRING we found to the list of substrings
(setq text (replace-match "" nil nil text))) ; remove SUBSTRING from text, and repeat while loop
(length substrings))) ; count number of items in substrings list
</syntaxhighlight>
{{out}}
<pre>
(count-substrings "the three truths" "th")
3
(count-substrings "ababababab" "abab")
2
</pre>
=={{header|Erlang}}==
<syntaxhighlight lang="erlang">
%% Count non-overlapping substrings in Erlang for the rosetta code wiki.
%% Implemented by J.W. Luiten
-module(substrings).
-export([main/2]).
%% String and Sub exhausted, count a match and present result
match([], [], _OrigSub, Acc) ->
Acc+1;
%% String exhausted, present result
match([], _Sub, _OrigSub, Acc) ->
Acc;
%% Sub exhausted, count a match
match(String, [], Sub, Acc) ->
match(String, Sub, Sub, Acc+1);
%% First character matches, advance
match([X|MainTail], [X|SubTail], Sub, Acc) ->
match(MainTail, SubTail, Sub, Acc);
%% First characters do not match. Keep scanning for sub in remainder of string
match([_X|MainTail], [_Y|_SubTail], Sub, Acc)->
match(MainTail, Sub, Sub, Acc).
main(String, Sub) ->
match(String, Sub, Sub, 0).</syntaxhighlight>
Command: <syntaxhighlight lang="erlang">substrings:main("ababababab","abab").</syntaxhighlight>
{{out}}
<pre>
2
</pre>
Alternative using built in functions:
<syntaxhighlight lang="erlang">
main( String, Sub ) -> erlang:length( binary:split(binary:list_to_bin(String), binary:list_to_bin(Sub), [global]) ) - 1.
</syntaxhighlight>
=={{header|Euphoria}}==
<syntaxhighlight lang="euphoria">function countSubstring(sequence s, sequence sub)
integer from,count
count = 0
from = 1
while 1 do
from = match_from(sub,s,from)
if not from then
exit
end if
from += length(sub)
count += 1
end while
return count
end function
? countSubstring("the three truths","th")
? countSubstring("ababababab","abab")</syntaxhighlight>
{{out}}
<pre>3
2
</pre>
=={{header|F_Sharp|F#}}==
"Remove and count the difference" method, as shown by J, Java, ...
<syntaxhighlight lang="fsharp">open System
let countSubstring (where :string) (what : string) =
match what with
| "" -> 0 // just a definition; infinity is not an int
| _ -> (where.Length - where.Replace(what, @"").Length) / what.Length
[<EntryPoint>]
let main argv =
let show where what =
printfn @"countSubstring(""%s"", ""%s"") = %d" where what (countSubstring where what)
show "the three truths" "th"
show "ababababab" "abab"
show "abc" ""
0</syntaxhighlight>
<pre>countSubstring("the three truths", "th") = 3
countSubstring("ababababab", "abab") = 2
countSubstring("abc", "") = 0</pre>
=={{header|Factor}}==
<syntaxhighlight lang="factor">USING: math sequences splitting ;
: occurences ( seq subseq -- n ) split-subseq length 1 - ;</syntaxhighlight>
=={{header|Forth}}==
<syntaxhighlight lang="forth">: str-count ( s1 len s2 len -- n )
2swap 0 >r
begin 2over search
while 2over nip /string
r> 1+ >r
repeat 2drop 2drop r> ;
s" the three truths" s" th" str-count . \ 3
s" ababababab" s" abab" str-count . \ 2</syntaxhighlight>
=={{header|Fortran}}==
{{works with|Fortran|90 and later}}
<
implicit none
integer :: n
Line 173 ⟶ 1,703:
if(posn == 0) return
c = c + 1
p = p + posn + len(s2) - 1
end do
end function
end program</
{{out}}
<pre>3
2
2</pre>
=={{header|FreeBASIC}}==
<syntaxhighlight lang="freebasic">' FB 1.05.0 Win64
Function countSubstring(s As String, search As String) As Integer
If s = "" OrElse search = "" Then Return 0
Dim As Integer count = 0, length = Len(search)
For i As Integer = 1 To Len(s)
If Mid(s, i, length) = Search Then
count += 1
i += length - 1
End If
Next
Return count
End Function
Print countSubstring("the three truths","th")
Print countSubstring("ababababab","abab")
Print countSubString("zzzzzzzzzzzzzzz", "z")
Print
Print "Press any key to quit"
Sleep</syntaxhighlight>
{{out}}
<pre>
3
2
15
</pre>
=={{header|FunL}}==
<syntaxhighlight lang="funl">import util.Regex
def countSubstring( str, substr ) = Regex( substr ).findAllMatchIn( str ).length()
println( countSubstring("the three truths", "th") )
println( countSubstring("ababababab", "abab") )</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Fōrmulæ}}==
{{FormulaeEntry|page=https://formulae.org/?script=examples/Count_occurrences_of_a_substring}}
=={{header|FutureBasic}}==
<syntaxhighlight lang="futurebasic">window 1
local fn CountSubstring( string as CFStringRef, substring as CFStringRef ) as long
end fn = fn ArrayCount( fn StringComponentsSeparatedByString( string, substring ) ) - 1
print fn CountSubstring( @"the three truths", @"th" )
print fn CountSubstring( @"ababababab", @"abab" )
HandleEvents</syntaxhighlight>
{{out}}
<pre>3
2
</pre>
=={{header|Gambas}}==
{{trans|FreeBASIC}}
<syntaxhighlight lang="vbnet">Public Sub Main()
Print countSubstring("the three truths", "th")
Print countSubstring("ababababab", "abab")
Print countSubString("zzzzzzzzzzzzzzz", "z")
End
Function countSubstring(s As String, search As String) As Integer
If s = "" Or search = "" Then Return 0
Dim count As Integer = 0, length As Integer = Len(search)
For i As Integer = 1 To Len(s)
If Mid(s, i, length) = Search Then
count += 1
i += length - 1
End If
Next
Return count
End Function</syntaxhighlight>
{{out}}
<pre>Same as FreeBASIC entry.</pre>
=={{header|Go}}==
Using strings.Count() method:
<syntaxhighlight lang="go">package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Count("the three truths", "th")) // says: 3
fmt.Println(strings.Count("ababababab", "abab")) // says: 2
}</syntaxhighlight>
=={{header|Groovy}}==
Solution, uses the Groovy "find" operator (=~), and the Groovy-extended Matcher property "count":
<syntaxhighlight lang="groovy">println (('the three truths' =~ /th/).count)
println (('ababababab' =~ /abab/).count)
println (('abaabba*bbaba*bbab' =~ /a*b/).count)
println (('abaabba*bbaba*bbab' =~ /a\*b/).count)</syntaxhighlight>
{{out}}
<pre>3
2
9
2</pre>
=={{header|Haskell}}==
=== Text-based solution ===
<syntaxhighlight lang="haskell">import Data.Text hiding (length)
-- Return the number of non-overlapping occurrences of sub in str.
Line 191 ⟶ 1,837:
print $ countSubStrs "the three truths" "th"
print $ countSubStrs "ababababab" "abab"
</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
Alternatively, in a language built around currying, it might make more sense to reverse the suggested order of arguments.
<syntaxhighlight lang="haskell">{-# LANGUAGE OverloadedStrings #-}
import Data.Text hiding (length)
--------- COUNT OF SUBSTRING INSTANCES IN A STRING -------
countAll :: Text -> Text -> Int
countAll needle haystack =
length
(breakOnAll needle haystack)
--------------------------- TEST -------------------------
main :: IO ()
main =
print $
countAll "ab"
<$> [ "ababababab",
"abelian absurdity",
"babel kebab"
]</syntaxhighlight>
{{Out}}
<pre>[5,2,2]</pre>
=== List-based solution ===
Even though list-based strings are not "the right" way of representing texts, the problem of counting subsequences in a list is generally useful.
<syntaxhighlight lang="haskell">count :: Eq a => [a] -> [a] -> Int
count [] = error "empty substring"
count sub = go
where
go = scan sub . dropWhile (/= head sub)
scan _ [] = 0
scan [] xs = 1 + go xs
scan (x:xs) (y:ys) | x == y = scan xs ys
| otherwise = go ys</syntaxhighlight>
{{Out}}
<pre>λ> count "th" "the three truths"
3
λ> count "abab" "ababababab"
2
λ> count [2,3] [1,2,1,2,3,4,3,2,3,4,3,2]
2
λ> count "123456" $ foldMap show [1..1000000]
7</pre>
=== List-based solution using Data.List ===
The following solution is almost two times faster than the previous one.
<syntaxhighlight lang="haskell">import Data.List (tails, stripPrefix)
import Data.Maybe (catMaybes)
count :: Eq a => [a] -> [a] -> Int
count sub = length . catMaybes . map (stripPrefix sub) . tails</syntaxhighlight>
=={{header|Icon}} and {{header|Unicon}}==
<syntaxhighlight lang="icon">procedure main()
every A := ![ ["the three truths","th"], ["ababababab","abab"] ] do
write("The string ",image(A[2])," occurs as a non-overlapping substring ",
countSubstring!A , " times in ",image(A[1]))
end
procedure countSubstring(s1,s2) #: return count of non-overlapping substrings
c := 0
s1 ? while tab(find(s2)) do {
move(*s2)
c +:= 1
}
return c
end</syntaxhighlight>
{{out}}
<pre>The string "th" occurs as a non-overlapping substring 3 times in "the three truths"
The string "abab" occurs as a non-overlapping substring 2 times in "ababababab"</pre>
=={{header|J}}==
<syntaxhighlight lang="j">require'strings'
countss=: #@] %~ #@[ - [ #@rplc '';~]</syntaxhighlight>
In other words: find length of original string, replace the string to be counted with the empty string, find the difference in lengths and divide by the length of the string to be counted.
Example use:
<syntaxhighlight lang="j"> 'the three truths' countss 'th'
3
'ababababab' countss 'abab'
2</syntaxhighlight>
=={{header|Java}}==
Using regular expression pattern matching
<syntaxhighlight lang="java">
int countSubstring(String string, String substring) {
substring = Pattern.quote(substring);
Pattern pattern = Pattern.compile(substring);
Matcher matcher = pattern.matcher(string);
int count = 0;
while (matcher.find())
count++;
return count;
}
</syntaxhighlight>
<br />
{{works with|Java|1.5+}}
The "remove and count the difference" method:
<
public static int countSubstring(String subStr, String str){
return (str.length() - str.replace(subStr, "").length()) / subStr.length();
Line 211 ⟶ 1,959:
System.out.println(countSubstring("a*b", "abaabba*bbaba*bbab"));
}
}</
{{out}}
<pre>3
2
2</pre>
{{works with|Java|1.5+}}
The "split and count" method:
<
public class CountSubstring {
Line 234 ⟶ 1,981:
System.out.println(countSubstring("a*b", "abaabba*bbaba*bbab"));
}
}</
{{out}}
<pre>3
2
2</pre>
Manual looping
<syntaxhighlight lang="java">public class CountSubstring {
public static int countSubstring(String subStr, String str){
int
loc = str.indexOf(subStr, loc + subStr.length()))
return
}
Line 260 ⟶ 2,002:
System.out.println(countSubstring("a*b", "abaabba*bbaba*bbab"));
}
}</
{{out}}
<pre>3
2
2</pre>
=={{header|JavaScript}}==
Using regexes:
<syntaxhighlight lang="javascript">function countSubstring(str, subStr) {
var matches = str.match(new RegExp(subStr, "g"));
return matches ? matches.length : 0;
}</syntaxhighlight>
Using 'split' and ES6 notation:
<syntaxhighlight lang="javascript">const countSubString = (str, subStr) => str.split(subStr).length - 1;
</syntaxhighlight>
=={{header|jq}}==
Using regexes (available in jq versions after June 19, 2014):
<syntaxhighlight lang="jq">
def countSubstring(sub):
[match(sub; "g")] | length;</syntaxhighlight>Example:<syntaxhighlight lang="jq">
"the three truths" | countSubstring("th")</syntaxhighlight>
=={{header|Julia}}==
'''Built-in Function'''
<pre>
matchall(r::Regex, s::String[, overlap::Bool=false]) -> Vector{String}
Return a vector of the matching substrings from eachmatch.
</pre>
'''Main'''
<syntaxhighlight lang="julia">
ts = ["the three truths", "ababababab"]
tsub = ["th", "abab"]
println("Test of non-overlapping substring counts.")
for i in 1:length(ts)
print(ts[i], " (", tsub[i], ") => ")
println(length(matchall(Regex(tsub[i]), ts[i])))
end
println()
println("Test of overlapping substring counts.")
for i in 1:length(ts)
print(ts[i], " (", tsub[i], ") => ")
println(length(matchall(Regex(tsub[i]), ts[i], true)))
end
</syntaxhighlight>
{{out}}
<pre>
Test of non-overlapping substring counts.
the three truths (th) => 3
ababababab (abab) => 2
Test of overlapping substring counts.
the three truths (th) => 3
ababababab (abab) => 4
</pre>
=={{header|K}}==
The dyadic verb _ss gives the positions of substring y in string x.
<syntaxhighlight lang="k"> "the three truths" _ss "th"
0 4 13
#"the three truths" _ss "th"
3
"ababababab" _ss "abab"
0 4
#"ababababab" _ss "abab"
2
</syntaxhighlight>
=={{header|Klingphix}}==
<syntaxhighlight lang="klingphix">include ..\Utilitys.tlhy
:count %s !s
0 >ps
[ps> 1 + >ps
$s len nip + snip nip] [$s find dup] while
drop drop ps>
;
"the three truths" "th" count ?
"ababababab" "abab" count ?
" " input</syntaxhighlight>
Other solution
<syntaxhighlight lang="klingphix">include ..\Utilitys.tlhy
:count "- " convert "-" 2 tolist split len nip ;
"the three truths" "th" count ?
"ababababab" "abab" count ?
" " input</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Kotlin}}==
<syntaxhighlight lang="scala">// version 1.0.6
fun countSubstring(s: String, sub: String): Int = s.split(sub).size - 1
fun main(args: Array<String>) {
println(countSubstring("the three truths","th"))
println(countSubstring("ababababab","abab"))
println(countSubstring("",""))
}</syntaxhighlight>
{{out}}
<pre>
3
2
1
</pre>
=={{header|Lambdatalk}}==
<syntaxhighlight lang="scheme">
{def countSubstring
{def countSubstring.r
{lambda {:n :i :acc :s}
{if {>= :i :n}
then :acc
else {countSubstring.r :n
{+ :i 1}
{if {W.equal? {W.get :i :s} ⫖}
then {+ :acc 1}
else :acc}
:s} }}}
{lambda {:w :s}
{countSubstring.r {W.length :s} 0 0
{S.replace \s by ⫕ in
{S.replace :w by ⫖ in :s}}}}}
-> countSubstring
{countSubstring th the three truths}
-> 3
{countSubstring ab ababa}
-> 2
{countSubstring aba ababa}
-> 1
</syntaxhighlight>
=={{header|langur}}==
<syntaxhighlight lang="langur">writeln len(indices("th", "the three truths"))
writeln len(indices("abab", "ababababab"))
</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Lasso}}==
<syntaxhighlight lang="lasso">define countSubstring(str::string, substr::string)::integer => {
local(i = 1, foundpos = -1, found = 0)
while(#i < #str->size && #foundpos != 0) => {
protect => {
handle_error => { #foundpos = 0 }
#foundpos = #str->find(#substr, -offset=#i)
}
if(#foundpos > 0) => {
#found += 1
#i = #foundpos + #substr->size
else
#i++
}
}
return #found
}
define countSubstring_bothways(str::string, substr::string)::integer => {
local(found = countSubstring(#str,#substr))
#str->reverse
local(found2 = countSubstring(#str,#substr))
#found > #found2 ? return #found | return #found2
}
countSubstring_bothways('the three truths','th')
//3
countSubstring_bothways('ababababab','abab')
//2</syntaxhighlight>
=={{header|Liberty BASIC}}==
<syntaxhighlight lang="lb">
print countSubstring( "the three truths", "th")
print countSubstring( "ababababab", "abab")
end
function countSubstring( a$, s$)
c =0
la =len( a$)
ls =len( s$)
for i =1 to la -ls
if mid$( a$, i, ls) =s$ then c =c +1: i =i +ls -1
next i
countSubstring =c
end function
</syntaxhighlight>
=={{header|Logtalk}}==
Using atoms for string representation:
<syntaxhighlight lang="logtalk">
:- object(counting).
:- public(count/3).
count(String, SubString, Count) :-
count(String, SubString, 0, Count).
count(String, SubString, Count0, Count) :-
( sub_atom(String, Before, Length, After, SubString) ->
Count1 is Count0 + 1,
Start is Before + Length,
sub_atom(String, Start, After, 0, Rest),
count(Rest, SubString, Count1, Count)
; Count is Count0
).
:- end_object.
</syntaxhighlight>
{{out}}
<syntaxhighlight lang="text">
| ?- counting::count('the three truths', th, N).
N = 3
yes
| ?- counting::count(ababababab, abab, N).
N = 2
yes
</syntaxhighlight>
=={{header|Lua}}==
Solution 1:
<syntaxhighlight lang="lua">function countSubstring(s1, s2)
return select(2, s1:gsub(s2, ""))
end
print(countSubstring("the three truths", "th"))
print(countSubstring("ababababab", "abab"))</syntaxhighlight>
<pre>3
2</pre>
Solution 2:
<syntaxhighlight lang="lua">function countSubstring(s1, s2)
local count = 0
for eachMatch in s1:gmatch(s2) do
count = count + 1
end
return count
end
print(countSubstring("the three truths", "th"))
print(countSubstring("ababababab", "abab"))</syntaxhighlight>
<pre>3
2</pre>
=={{header|MACRO-11}}==
<syntaxhighlight lang="macro11"> .TITLE CSUBS
.MCALL .TTYOUT,.EXIT
CSUBS:: JMP DEMO
; COUNT SUBSTRINGS R1 IN R0
COUNT: CLR R2
BR 4$
1$: MOV R0,R3
MOV R1,R4
2$: CMPB (R3)+,(R4)+
BEQ 2$
TSTB -(R4)
BNE 3$
INC R2
DEC R3
MOV R3,R0
BR 4$
3$: INC R0
4$: TSTB (R0)
BNE 1$
RTS PC
; TEST EXAMPLES
DEMO: MOV #ST1,R0
MOV #SU1,R1
JSR PC,1$
MOV #ST2,R0
MOV #SU2,R1
JSR PC,1$
.EXIT
1$: JSR PC,COUNT
ADD #60,R2
MOVB R2,3$
MOV #3$,R2
2$: MOVB (R2)+,R0
.TTYOUT
BNE 2$
RTS PC
3$: .BYTE 0,15,12,0
ST1: .ASCIZ /THE THREE TRUTHS/
SU1: .ASCIZ /TH/
ST2: .ASCIZ /ABABABABAB/
SU2: .ASCIZ /ABAB/
.END CSUBS</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Maple}}==
<syntaxhighlight lang="maple">
f:=proc(s::string,c::string,count::nonnegint) local n;
n:=StringTools:-Search(c,s);
if n>0 then 1+procname(s[n+length(c)..],c,count);
else 0; end if;
end proc:
f("the three truths","th",0);
f("ababababab","abab",0);
</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Mathematica}} / {{header|Wolfram Language}}==
<syntaxhighlight lang="mathematica">StringPosition["the three truths","th",Overlaps->False]//Length
3
StringPosition["ababababab","abab",Overlaps->False]//Length
2</syntaxhighlight>
=={{header|MATLAB}} / {{header|Octave}}==
<syntaxhighlight lang="matlab"> % Count occurrences of a substring without overlap
length(findstr("ababababab","abab",0))
length(findstr("the three truths","th",0))
% Count occurrences of a substring with overlap
length(findstr("ababababab","abab",1)) </syntaxhighlight>
{{out}}
<pre>
>> % Count occurrences of a substring without overlap
>> length(findstr("ababababab","abab",0))
ans = 2
>> length(findstr("the three truths","th",0))
ans = 3
>> % Count occurrences of a substring with overlap
>> length(findstr("ababababab","abab",1))
ans = 4
>> </pre>
=={{header|Maxima}}==
<syntaxhighlight lang="maxima">scount(e, s) := block(
[n: 0, k: 1],
while integerp(k: ssearch(e, s, k)) do (n: n + 1, k: k + 1),
n
)$
scount("na", "banana");
2</syntaxhighlight>
=={{header|MiniScript}}==
<syntaxhighlight lang="miniscript">string.count = function(s)
return self.split(s).len - 1
end function
print "the three truths".count("th")
print "ababababab".count("abab")</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Mirah}}==
<syntaxhighlight lang="mirah">import java.util.regex.Pattern
import java.util.regex.Matcher
#The "remove and count the difference" method
def count_substring(pattern:string, source:string)
(source.length() - source.replace(pattern, "").length()) / pattern.length()
end
puts count_substring("th", "the three truths") # ==> 3
puts count_substring("abab", "ababababab") # ==> 2
puts count_substring("a*b", "abaabba*bbaba*bbab") # ==> 2
# The "split and count" method
def count_substring2(pattern:string, source:string)
# the result of split() will contain one more element than the delimiter
# the "-1" second argument makes it not discard trailing empty strings
source.split(Pattern.quote(pattern), -1).length - 1
end
puts count_substring2("th", "the three truths") # ==> 3
puts count_substring2("abab", "ababababab") # ==> 2
puts count_substring2("a*b", "abaabba*bbaba*bbab") # ==> 2
# This method does a match and counts how many times it matches
def count_substring3(pattern:string, source:string)
result = 0
Matcher m = Pattern.compile(Pattern.quote(pattern)).matcher(source);
while (m.find())
result = result + 1
end
result
end
puts count_substring3("th", "the three truths") # ==> 3
puts count_substring3("abab", "ababababab") # ==> 2
puts count_substring3("a*b", "abaabba*bbaba*bbab") # ==> 2
</syntaxhighlight>
=={{header|Miranda}}==
<syntaxhighlight lang="miranda">main :: [sys_message]
main = [Stdout (show (countSubstring "the three truths" "th") ++ "\n"),
Stdout (show (countSubstring "ababababab" "abab") ++ "\n")]
countSubstring :: [*]->[*]->num
countSubstring str ss
= 0, if str = []
= 1 + countSubstring (drop len str) ss, if match
= countSubstring (tl str) ss, otherwise
where len = #ss
match = take len str = ss</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Nanoquery}}==
{{trans|Java}}
<syntaxhighlight lang="nanoquery">def countSubstring(str, subStr)
return int((len(str) - len(str.replace(subStr, ""))) / len(subStr))
end</syntaxhighlight>
=={{header|Nemerle}}==
{{trans|F#}}
<syntaxhighlight lang="nemerle">using System.Console;
module CountSubStrings
{
CountSubStrings(this text : string, target : string) : int
{
match (target) {
|"" => 0
|_ => (text.Length - text.Replace(target, "").Length) / target.Length
}
}
Main() : void
{
def text1 = "the three truths";
def target1 = "th";
def text2 = "ababababab";
def target2 = "abab";
WriteLine($"$target1 occurs $(text1.CountSubStrings(target1)) times in $text1");
WriteLine($"$target2 occurs $(text2.CountSubStrings(target2)) times in $text2");
}
}</syntaxhighlight>
{{out}}
<pre>th occurs 3 times in the three truths
abab occurs 2 times in ababababab</pre>
=={{header|NetRexx}}==
NetRexx provides the <tt>''string''.countstr(''needle'')</tt> built-in function:
<syntaxhighlight lang="netrexx">/* NetRexx */
options replace format comments java crossref symbols nobinary
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method countSubstring(inStr, findStr) public static
return inStr.countstr(findStr)
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method main(args = String[]) public static
strings = ''
find = 'FIND'
ix = 0
ix = ix + 1; strings[0] = ix; find[0] = ix; strings[ix] = 'the three truths'; strings[ix, find] = 'th'
ix = ix + 1; strings[0] = ix; find[0] = ix; strings[ix] = 'ababababab'; strings[ix, find] = 'abab'
loop ix = 1 to strings[0]
str = strings[ix]
fnd = strings[ix, find]
say 'there are' countSubstring(str, fnd) 'occurences of "'fnd'" in "'str'"'
end ix
return
</syntaxhighlight>
{{out}}
<pre>
there are 3 occurences of "th" in "the three truths"
there are 2 occurences of "abab" in "ababababab"
</pre>
=={{header|NewLISP}}==
<syntaxhighlight lang="newlisp">; file: stringcount.lsp
; url: http://rosettacode.org/wiki/Count_occurrences_of_a_substring
; author: oofoe 2012-01-29
; Obvious (and non-destructive...)
; Note that NewLISP performs an /implicit/ slice on a string or list
; with this form "(start# end# stringorlist)". If the end# is omitted,
; the slice will go to the end of the string. This is handy here to
; keep removing the front part of the string as it gets matched.
(define (scount needle haystack)
(let ((h (copy haystack)) ; Copy of haystack string.
(i 0) ; Cursor.
(c 0)) ; Count of occurences.
(while (setq i (find needle h))
(inc c)
(setq h ((+ i (length needle)) h)))
c)) ; Return count.
; Tricky -- Uses functionality from replace function to find all
; non-overlapping occurrences, replace them, and return the count of
; items replaced in system variable $0.
(define (rcount needle haystack)
(replace needle haystack "X") $0)
; Test
(define (test f needle haystack)
(println "Found " (f needle haystack)
" occurences of '" needle "' in '" haystack "'."))
(dolist (f (list scount rcount))
(test f "glart" "hinkerpop")
(test f "abab" "ababababab")
(test f "th" "the three truths")
(println)
)
(exit)</syntaxhighlight>
{{out}}
<pre>Found 0 occurences of 'glart' in 'hinkerpop'.
Found 2 occurences of 'abab' in 'ababababab'.
Found 3 occurences of 'th' in 'the three truths'.
Found 0 occurences of 'glart' in 'hinkerpop'.
Found 2 occurences of 'abab' in 'ababababab'.
Found 3 occurences of 'th' in 'the three truths'.
</pre>
=={{header|Nim}}==
<syntaxhighlight lang="nim">import strutils
proc count(s, sub: string): int =
var i = 0
while true:
i = s.find(sub, i)
if i < 0:
break
i += sub.len # i += 1 for overlapping substrings
inc result
echo count("the three truths","th")
echo count("ababababab","abab")</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Objective-C}}==
The "split and count" method:
<syntaxhighlight lang="objc">@interface NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr;
@end
@implementation NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr {
return [[self componentsSeparatedByString:subStr] count] - 1;
}
@end
int main(int argc, const char *argv[]) {
@autoreleasepool {
NSLog(@"%lu", [@"the three truths" occurrencesOfSubstring:@"th"]);
NSLog(@"%lu", [@"ababababab" occurrencesOfSubstring:@"abab"]);
NSLog(@"%lu", [@"abaabba*bbaba*bbab" occurrencesOfSubstring:@"a*b"]);
}
return 0;
}</syntaxhighlight>
{{out}}
<pre>3
2
2</pre>
The "remove and count the difference" method:
<syntaxhighlight lang="objc">@interface NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr;
@end
@implementation NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr {
return ([self length] - [[self stringByReplacingOccurrencesOfString:subStr withString:@""] length]) / [subStr length];
}
@end
int main(int argc, const char *argv[]) {
@autoreleasepool {
NSLog(@"%lu", [@"the three truths" occurrencesOfSubstring:@"th"]);
NSLog(@"%lu", [@"ababababab" occurrencesOfSubstring:@"abab"]);
NSLog(@"%lu", [@"abaabba*bbaba*bbab" occurrencesOfSubstring:@"a*b"]);
}
return 0;
}</syntaxhighlight>
{{out}}
<pre>3
2
2</pre>
Manual looping:
<syntaxhighlight lang="objc">@interface NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr;
@end
@implementation NSString (CountSubstrings)
- (NSUInteger)occurrencesOfSubstring:(NSString *)subStr {
NSUInteger count = 0;
for (NSRange range = [self rangeOfString:subStr]; range.location != NSNotFound;
range.location += range.length,
range = [self rangeOfString:subStr options:0
range:NSMakeRange(range.location, [self length] - range.location)])
count++;
return count;
}
@end
int main(int argc, const char *argv[]) {
@autoreleasepool {
NSLog(@"%lu", [@"the three truths" occurrencesOfSubstring:@"th"]);
NSLog(@"%lu", [@"ababababab" occurrencesOfSubstring:@"abab"]);
NSLog(@"%lu", [@"abaabba*bbaba*bbab" occurrencesOfSubstring:@"a*b"]);
}
return 0;
}</syntaxhighlight>
{{out}}
<pre>3
2
2</pre>
=={{header|OCaml}}==
<syntaxhighlight lang="ocaml">let count_substring str sub =
let sub_len = String.length sub in
let len_diff = (String.length str) - sub_len
and reg = Str.regexp_string sub in
let rec aux i n =
if i > len_diff then n else
try
let pos = Str.search_forward reg str i in
aux (pos + sub_len) (succ n)
with Not_found -> n
in
aux 0 0
let () =
Printf.printf "count 1: %d\n" (count_substring "the three truth" "th");
Printf.printf "count 2: %d\n" (count_substring "ababababab" "abab");
;;</syntaxhighlight>
=={{header|Oforth}}==
<syntaxhighlight lang="oforth">
: countSubString(s, sub)
0 1 while(sub swap s indexOfAllFrom dup notNull) [ sub size + 1 under+ ]
drop ;</syntaxhighlight>
{{out}}
<pre>
countSubString("the three truths", "th") println
3
countSubString("ababababab", "abab") println
2
</pre>
=={{header|ooRexx}}==
<syntaxhighlight lang="oorexx">
bag="the three truths"
x="th"
say left(bag,30) left(x,15) 'found' bag~countstr(x)
bag="ababababab"
x="abab"
say left(bag,30) left(x,15) 'found' bag~countstr(x)
-- can be done caselessly too
bag="abABAbaBab"
x="abab"
say left(bag,30) left(x,15) 'found' bag~caselesscountstr(x)
</syntaxhighlight>
{{out}}
<pre style="height:10ex;overflow:scroll">
the three truths th found 3
ababababab abab found 2
abABAbaBab abab found 2
</pre>
=={{header|PARI/GP}}==
<syntaxhighlight lang="parigp">subvec(v,u)={
my(i=1,s);
while(i+#u<=#v,
for(j=1,#u,
if(v[i+j-1]!=u[j], i++; next(2))
);
s++;
i+=#u
);
s
};
substr(s1,s2)=subvec(Vec(s1),Vec(s2));
substr("the three truths","th")
substr("ababababab","abab")</syntaxhighlight>
{{out}}
<pre>%1 = 3
%2 = 2</pre>
=={{header|Pascal}}==
See [[Count_occurrences_of_a_substring#Delphi | Delphi]]
=={{header|Perl}}==
<
my $str = shift;
my $sub = quotemeta(shift);
Line 276 ⟶ 2,758:
print countSubstring("the three truths","th"), "\n"; # prints "3"
print countSubstring("ababababab","abab"), "\n"; # prints "2"</
=={{header|Phix}}==
<!--<syntaxhighlight lang="phix">(phixonline)-->
<span style="color: #004080;">sequence</span> <span style="color: #000000;">tests</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{</span><span style="color: #008000;">"the three truths"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"th"</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{</span><span style="color: #008000;">"ababababab"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"abab"</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{</span><span style="color: #008000;">"ababababab"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"aba"</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{</span><span style="color: #008000;">"ababababab"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ab"</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{</span><span style="color: #008000;">"ababababab"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"a"</span><span style="color: #0000FF;">},</span>
<span style="color: #0000FF;">{</span><span style="color: #008000;">"ababababab"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">""</span><span style="color: #0000FF;">}}</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">count</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">test</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">substring</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tests</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">start</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
<span style="color: #000000;">count</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #0000FF;">{</span><span style="color: #000000;">test</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">substring</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">tests</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">start</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">match</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">substring</span><span style="color: #0000FF;">,</span><span style="color: #000000;">test</span><span style="color: #0000FF;">,</span><span style="color: #000000;">start</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">start</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">start</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">substring</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">count</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"The string \"%s\" occurs as a non-overlapping substring %d times in \"%s\"\n"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">substring</span><span style="color: #0000FF;">,</span><span style="color: #000000;">count</span><span style="color: #0000FF;">,</span><span style="color: #000000;">test</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
The string "th" occurs as a non-overlapping substring 3 times in "the three truths"
The string "abab" occurs as a non-overlapping substring 2 times in "ababababab"
The string "aba" occurs as a non-overlapping substring 2 times in "ababababab"
The string "ab" occurs as a non-overlapping substring 5 times in "ababababab"
The string "a" occurs as a non-overlapping substring 5 times in "ababababab"
The string "" occurs as a non-overlapping substring 0 times in "ababababab"
</pre>
=={{header|PHP}}==
<
echo substr_count("the three truths", "th"),
echo substr_count("ababababab", "abab"),
</syntaxhighlight>
=={{header|Picat}}==
Picat has a predicate for searching for substrings (find/4) but on backtracking (e.g. in a findall/2 wrapper) it yields all overlapping substrings which is not correct in this task.
So we have to roll our own. Here are two versions.
===Recursion===
<syntaxhighlight lang="picat">count_substrings_rec(S, SB) = C =>
count_rec(S,SB,0,C).
count_rec([],_SB,Count,Count).
count_rec(SBRest,SB,Count0,Count) :-
SBRest = SB ++ Rest, % "split" into substring and the rest of the string
count_rec(Rest,SB,Count0+1,Count).
count_rec([T|Rest],SB,Count0,Count) :-
T != SB, % this character is not a substring
count_rec(Rest,SB,Count0,Count).</syntaxhighlight>
===Iterative===
Iterative version using find/4 (wrap with once/1 to avoid backtracking).
{{trans|Euphoria}}
<syntaxhighlight lang="picat">count_substrings_find(S, SB) = C =>
SLen = S.len,
Count = 0,
From = 1,
while (From <= SLen)
(
once(find(slice(S,From),SB,_From2,To)) ->
Count := Count + 1,
From := From + To
;
From := From + 1
)
end,
C = Count.</syntaxhighlight>
The time differences between these two versions are quite large which is shown in a benchmark of searching the substring "ab" in a string of 100 000 random characters from the set of "abcde":
* count_substrings_rec/2: 0.009s
* count_substrings_find: 0.501s
=={{header|PicoLisp}}==
<
(let (Cnt 0 H (chop Sub))
(for (S (chop Str) S (cdr S))
Line 297 ⟶ 2,846:
(inc 'Cnt)
(setq S (map prog2 H S)) ) )
Cnt ) )</
Test:
<pre>: (countSubstring "the three truths" "th")
Line 304 ⟶ 2,853:
: (countSubstring "ababababab" "abab")
-> 2</pre>
=={{header|Pike}}==
<syntaxhighlight lang="pike">
write("%d %d\n",
String.count("the three truths", "th"),
String.count("ababababab", "abab"));
</syntaxhighlight>
{{Out}}
<pre>
3 2
</pre>
=={{header|PL/I}}==
<syntaxhighlight lang="pli">cnt: procedure options (main);
declare (i, tally) fixed binary;
declare (text, key) character (100) varying;
get edit (text) (L); put skip data (text);
get edit (key) (L); put skip data (key);
tally = 0; i = 1;
do until (i = 0);
i = index(text, key, i);
if i > 0 then do; tally = tally + 1; i = i + length(key); end;
end;
put skip list (tally);
end cnt;</syntaxhighlight>
Output for the two specified strings is as expected.
{{out}} for the following data:
<pre>
TEXT='AAAAAAAAAAAAAAA';
KEY='AA';
7
</pre>
=={{header|PL/M}}==
<syntaxhighlight lang="plm">100H:
/* CP/M CALLS */
BDOS: PROCEDURE (FN, ARG); DECLARE FN BYTE, ARG ADDRESS; GO TO 5; END BDOS;
EXIT: PROCEDURE; CALL BDOS(0, 0); END EXIT;
PRINT: PROCEDURE (S); DECLARE S ADDRESS; CALL BDOS(9, S); END PRINT;
/* PRINT A NUMBER */
PRINT$NUMBER: PROCEDURE (N);
DECLARE S (8) BYTE INITIAL ('.....',13,10,'$');
DECLARE (P, N) ADDRESS, C BASED P BYTE;
P = .S(5);
DIGIT:
P = P - 1;
C = N MOD 10 + '0';
N = N / 10;
IF N > 0 THEN GO TO DIGIT;
CALL PRINT(P);
END PRINT$NUMBER;
/* COUNT OCCURRENCES OF SUBSTRING IN STRING */
COUNT$SUBSTRING: PROCEDURE (STR, MATCH) ADDRESS;
DECLARE (STR, MATCH) ADDRESS, C BASED STR BYTE;
DECLARE (SP, MP) ADDRESS, (SC BASED SP, MC BASED MP) BYTE;
DECLARE COUNT ADDRESS;
COUNT = 0;
DO WHILE C <> '$';
SP = STR;
MP = MATCH;
DO WHILE SC = MC;
SP = SP + 1;
MP = MP + 1;
END;
IF MC = '$' THEN DO;
STR = SP;
COUNT = COUNT + 1;
END;
ELSE DO;
STR = STR + 1;
END;
END;
RETURN COUNT;
END COUNT$SUBSTRING;
CALL PRINT$NUMBER(COUNT$SUBSTRING(.'THE THREE TRUTHS$', .'TH$')); /* PRINTS 3 */
CALL PRINT$NUMBER(COUNT$SUBSTRING(.'ABABABABAB$', .'ABAB$')); /* PRINTS 2 */
CALL PRINT$NUMBER(COUNT$SUBSTRING(.'CAT$', .'DOG$')); /* PRINTS 0 */
CALL EXIT;
EOF</syntaxhighlight>
{{out}}
<pre>3
2
0</pre>
=={{header|PowerBASIC}}==
{{works with|PB/Win}}
{{works with|PB/CC}}
Windows versions of PowerBASIC (at least since PB/Win 7, and possibly earlier) provide the <code>TALLY</code> function, which does exactly what this task requires (count non-overlapping substrings).
[[PB/DOS]] can use the example under [[#BASIC|BASIC]], above.
Note that while this example is marked as working with PB/Win, the <code>PRINT</code> statement would need to be replaced with <code>MSGBOX</code>, or output to a file. (PB/Win does not support console output.)
<syntaxhighlight lang="powerbasic">FUNCTION PBMAIN () AS LONG
PRINT "the three truths, th:", TALLY("the three truths", "th")
PRINT "ababababab, abab:", TALLY("ababababab", "abab")
END FUNCTION</syntaxhighlight>
{{out}}
the three truths, th: 3
ababababab, abab: 2
=={{header|PowerShell}}==
{{works with|PowerShell|4.0}}
<syntaxhighlight lang="powershell">
[regex]::Matches("the three truths", "th").count
</syntaxhighlight>
<b>Output:</b>
<pre>
3
</pre>
<syntaxhighlight lang="powershell">
[regex]::Matches("ababababab","abab").count
</syntaxhighlight>
<b>Output:</b>
<pre>
2
</pre>
=={{header|Prolog}}==
{{works with|SWI-Prolog|7}}
Using SWI-Prolog's string facilities (this solution is very similar to the Logtalk solution that uses sub_atom/5):
<syntaxhighlight lang="prolog">
count_substring(String, Sub, Total) :-
count_substring(String, Sub, 0, Total).
count_substring(String, Sub, Count, Total) :-
( substring_rest(String, Sub, Rest)
->
succ(Count, NextCount),
count_substring(Rest, Sub, NextCount, Total)
;
Total = Count
).
substring_rest(String, Sub, Rest) :-
sub_string(String, Before, Length, Remain, Sub),
DropN is Before + Length,
sub_string(String, DropN, Remain, 0, Rest).
</syntaxhighlight>
Usage:
<syntaxhighlight lang="prolog">
?- count_substring("the three truths","th",X).
X = 3.
?- count_substring("ababababab","abab",X).
X = 2.
</syntaxhighlight>
=== version using DCG ===
{{works with|SWI-Prolog|7.6.4}}
<syntaxhighlight lang="prolog">
:- system:set_prolog_flag(double_quotes,chars) .
occurrences(TARGETz0,SUBSTRINGz0,COUNT)
:-
prolog:phrase(occurrences(SUBSTRINGz0,0,COUNT),TARGETz0)
.
occurrences("",_,_)
-->
! ,
{ false }
.
occurrences(SUBSTRINGz0,COUNT0,COUNT)
-->
SUBSTRINGz0 ,
! ,
{ COUNT1 is COUNT0 + 1 } ,
occurrences(SUBSTRINGz0,COUNT1,COUNT)
.
occurrences(SUBSTRINGz0,COUNT0,COUNT)
-->
[_] ,
! ,
occurrences(SUBSTRINGz0,COUNT0,COUNT)
.
occurrences(_SUBSTRINGz0_,COUNT,COUNT)
-->
!
.
</syntaxhighlight>
{{out}}
<pre>
/*
?- occurrences("the three truths","th",COUNT) .
COUNT = 3.
?- occurrences("the three truths","",COUNT) .
false .
?- occurrences("ababababab","abab",COUNT) .
COUNT = 2.
?- occurrences("ababababab","",COUNT) .
false .
?-
*/
</pre>
=={{header|PureBasic}}==
<
b = CountString("ababababab","abab")
; a = 3
; b = 2</
=={{header|Python}}==
<
3
>>> "ababababab".count("abab")
2</
=={{header|Quackery}}==
Quackery does not come equipped with a "find substring m within string n" function, but one is defined in The Book of Quackery, as a demonstration of creating a finite state machine in Quackery. It is reproduced here with permission.
<syntaxhighlight lang="quackery"> [ [] 95 times
[ i^ space +
join ] ] constant is alphabet ( --> $ )
[ [ 2dup != while
-1 split drop
swap 1 split
unrot drop again ]
drop size ] is overlap ( [ [ --> n )
[ temp put [] swap
alphabet witheach
[ over -1 poke
over overlap
dup temp share
= if negate
swap dip join ]
drop temp release ] is eachend ( [ n --> [ )
[ [] swap
dup temp put
size times
[ temp share
i 1+ split drop
temp share size eachend
nested swap join ]
temp release ] is buildfsm ( $ --> [ )
[ dup [] = iff -1
else
[ behead
dup carriage = if
[ drop space ]
space - ]
swap ] is nextcharn ( $ --> n $ )
[ swap dup size
swap temp put
swap 0
[ over swap peek
temp take
nextcharn
temp put
dup 0 < iff
[ 2drop 0 ] done
peek
dup 0 < until ]
nip
temp take size - + ] is usefsm ( $ [ --> n )
[ over size 0 = iff
[ 2drop 0 ]
else
[ swap buildfsm
usefsm ] ] is find$ ( $ $ --> n )</syntaxhighlight>
<code>find$</code> builds a finite state machine to search for m, (an O(m³) operation), then uses it to search in n with O(n). Rather than use <code>find$</code>, and repeatedly build the same fsm, we will define a word <code>findall$</code> which returns a nest (i.e. list) of positions of m within n. (It actually returns the positions of the end of the substring, relative to (for the first instance) the start of the string, or (for subsequent instances) the end of the previous instance of the substring.)
<syntaxhighlight lang="quackery"> [ over size 0 = iff
[ 2drop [] ] done
[] unrot
swap buildfsm
[ 2dup usefsm
rot 2dup found while
dip [ over size + ]
dip
[ rot over join
unrot ]
swap split
nip swap again ]
2drop drop ] is findall$ ( $ $ --> [ )
</syntaxhighlight>
{{out}}
Testing <code>findall$</code> in the Quackery shell.
<pre>O> $ "th" $ "the three truths" tuck findall$
... witheach [ split swap echo$ cr ]
... echo$
...
th
e th
ree truth
s
Stack empty.
</pre>
Finally we can use <code>findall$</code> to fulfil the task requirements.
<syntaxhighlight lang="quackery"> [ swap findall$ size ] is occurences ( $ $ --> n )
$ "the three truths" $ "th" occurences echo cr
$ "ababababab" $ "abab" occurences echo cr
</syntaxhighlight>
{{out}}
<pre>3
2
</pre>
=={{header|R}}==
The <code>fixed</code> parameter (and, in <code>stringr</code>, the function of the same name) is used to specify a search for a fixed string. Otherwise, the search pattern is interpreted as a POSIX regular expression. PCRE is also an option: use the <code>perl</code> parameter or function.
<syntaxhighlight lang="rsplus">count = function(haystack, needle)
{v = attr(gregexpr(needle, haystack, fixed = T)[[1]], "match.length")
if (identical(v, -1L)) 0 else length(v)}
print(count("hello", "l"))</syntaxhighlight>
{{libheader|stringr}}
<syntaxhighlight lang="rsplus">library(stringr)
print(str_count("hello", fixed("l")))</syntaxhighlight>
=={{header|Racket}}==
<syntaxhighlight lang="racket">
(define count-substring
(compose length regexp-match*))
</syntaxhighlight>
<syntaxhighlight lang="racket">
> (count-substring "th" "the three truths")
3
> (count-substring "abab" "ababababab")
2
</syntaxhighlight>
=={{header|Raku}}==
(formerly Perl 6)
<syntaxhighlight lang="raku" line>sub count-substring($big, $little) { +$big.comb: / :r $little / }
say count-substring("the three truths", "th"); # 3
say count-substring("ababababab", "abab"); # 2
say count-substring(123123123, 12); # 3</syntaxhighlight>
The <tt>:r</tt> adverb makes the regex "ratchet forward" and skip any overlapping matches. <tt>.comb</tt> - when given a <tt>Regex</tt> as an argument - returns instances of that substring. Also, prefix <tt>+</tt> forces numeric context in Raku (it's a no-op in Perl 5). For the built in listy types that is the same as calling <tt>.elems</tt> method. One other style point: we now tend to prefer hyphenated names over camelCase.
=={{header|Red}}==
<syntaxhighlight lang="red">Red []
count-occurrences: function [string substring] [
length? parse string [collect [some [keep substring to substring]]]
]
test-case-1: "the three truths"
test-case-2: "ababababab"
print [test-case-1 "-" count-occurrences test-case-1 "th"]
print [test-case-2 "-" count-occurrences test-case-2 "abab"]
</syntaxhighlight>
{{out}}
<pre>the three truths - 3
ababababab - 2
</pre>
=={{header|Refal}}==
<syntaxhighlight lang="refal">$ENTRY Go {
= <Prout <Count ('th') 'the three truths'>>
<Prout <Count ('abab') 'abababab'>>;
};
Count {
(e.item) e.item e.rest = <+ 1 <Count (e.item) e.rest>>;
(e.item) s.x e.rest = <Count (e.item) e.rest>;
(e.item) = 0;
};</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|REXX}}==
Some older REXXes don't have the built-in function '''countstr''', so one is included within the REXX program as a function.
The '''countstr''' subroutine (below) mimics the BIF in newer REXXes (except for error checking).
Either of the first two strings may be null.
The third argument is optional and is the ''start position'' to start counting (the default is '''1''', meaning the first character).
<br>If specified, it must be a positive integer (and it may exceed the length of the 1<sup>st</sup> string).
The third argument was added here to be compatible with the newer REXXes BIF.
No checks are made (in the '''countstr''' subroutine) for:
::::* missing arguments
::::* too many arguments
::::* if '''start''' is a positive integer (when specified)
<syntaxhighlight lang="rexx">/*REXX program counts the occurrences of a (non─overlapping) substring in a string. */
w=. /*max. width so far.*/
bag= 'the three truths' ; x= "th" ; call showResult
bag= 'ababababab' ; x= "abab" ; call showResult
bag= 'aaaabacad' ; x= "aa" ; call showResult
bag= 'abaabba*bbaba*bbab' ; x= "a*b" ; call showResult
bag= 'abaabba*bbaba*bbab' ; x= " " ; call showResult
bag= ; x= "a" ; call showResult
bag= ; x= ; call showResult
bag= 'catapultcatalog' ; x= "cat" ; call showResult
bag= 'aaaaaaaaaaaaaa' ; x= "aa" ; call showResult
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
countstr: procedure; parse arg haystack,needle,start; if start=='' then start=1
width=length(needle)
do $=0 until p==0; p=pos(needle,haystack,start)
start=width + p /*prevent overlaps.*/
end /*$*/
return $ /*return the count.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
showResult: if w==. then do; w=30 /*W: largest haystack width.*/
say center('haystack',w) center('needle',w%2) center('count',5)
say left('', w, "═") left('', w%2, "═") left('', 5, "═")
end
if bag=='' then bag= " (null)" /*handle displaying of nulls.*/
if x=='' then x= " (null)" /* " " " " */
say left(bag, w) left(x, w%2) center(countstr(bag, x), 5)
return</syntaxhighlight>
'''output''' when using the default (internal) inputs:
<pre>
haystack needle count
══════════════════════════════ ═══════════════ ═════
the three truths th 3
ababababab abab 2
aaaabacad aa 2
abaabba*bbaba*bbab a*b 2
abaabba*bbaba*bbab 0
(null) a 0
(null) (null) 1
catapultcatalog cat 2
aaaaaaaaaaaaaa aa 7
</pre>
=={{header|Ring}}==
<syntaxhighlight lang="ring">
aString = "Ring Welcome Ring to the Ring Ring Programming Ring Language Ring"
bString = "Ring"
see count(aString,bString)
func count cString,dString
sum = 0
while substr(cString,dString) > 0
sum++
cString = substr(cString,substr(cString,dString)+len(string(sum)))
end
return sum</syntaxhighlight>
Output:
<pre>
6
</pre>
=={{header|RPL}}==
{{works with|Halcyon Calc|4.2.7}}
≪ DUP SIZE 1 - → str substr subsize
≪ 0
1 str SIZE subsize + '''FOR''' j
str j DUP subsize + SUB
'''IF''' substr == '''THEN'''
1 +
j subsize + 'j' STO
'''END'''
'''NEXT'''
≫ ≫ '<span style="color:blue">CNTSUB</span>' STO
"the three truths" <span style="color:blue">CNTSUB</span>
"ababababab" <span style="color:blue">CNTSUB</span>
{{out}}
<pre>
2: 3
1: 2
</pre>
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">def countSubstrings str, subStr
str.scan(subStr).length
end
p countSubstrings "the three truths", "th" #=> 3
p countSubstrings "ababababab", "abab" #=> 2</syntaxhighlight>
String#scan returns an array of substrings, and Array#length (or Array#size) counts them.
=={{header|Run BASIC}}==
<syntaxhighlight lang="runbasic">print countSubstring("the three truths","th")
print countSubstring("ababababab","abab")
FUNCTION countSubstring(s$,find$)
WHILE instr(s$,find$,i) <> 0
countSubstring = countSubstring + 1
i = instr(s$,find$,i) + len(find$)
WEND
END FUNCTION</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Rust}}==
<syntaxhighlight lang="rust">
fn main() {
println!("{}","the three truths".matches("th").count());
println!("{}","ababababab".matches("abab").count());
}
</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Scala}}==
===Using Recursion===
<syntaxhighlight lang="scala">import scala.annotation.tailrec
def countSubstring(str1:String, str2:String):Int={
@tailrec def count(pos:Int, c:Int):Int={
val idx=str1 indexOf(str2, pos)
if(idx == -1) c else count(idx+str2.size, c+1)
}
count(0,0)
}</syntaxhighlight>
===Using Sliding===
<syntaxhighlight lang="scala">def countSubstring(str: String, sub: String): Int =
str.sliding(sub.length).count(_ == sub)</syntaxhighlight><br/>
===Using Regular Expressions===
<syntaxhighlight lang="scala">def countSubstring( str:String, substr:String ) = substr.r.findAllMatchIn(str).length</syntaxhighlight>
<br/>
<syntaxhighlight lang="scala">println(countSubstring("ababababab", "abab"))
println(countSubstring("the three truths", "th"))</syntaxhighlight>
{{out}}
<pre>2
3</pre>
=={{header|Scheme}}==
{{works with|Gauche Scheme}}
<syntaxhighlight lang="scheme">gosh> (use gauche.lazy)
#<undef>
gosh> (length (lrxmatch "th" "the three truths"))
3
gosh> (length (lrxmatch "abab" "ababababab"))
2
</syntaxhighlight>
=={{header|Seed7}}==
<syntaxhighlight lang="seed7">$ include "seed7_05.s7i";
const func integer: countSubstring (in string: stri, in string: searched) is func
result
var integer: count is 0;
local
var integer: offset is 0;
begin
offset := pos(stri, searched);
while offset <> 0 do
incr(count);
offset := pos(stri, searched, offset + length(searched));
end while;
end func;
const proc: main is func
begin
writeln(countSubstring("the three truths", "th"));
writeln(countSubstring("ababababab", "abab"));
end func;</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|SETL}}==
<syntaxhighlight lang="setl">program count_overlapping_substrings;
tests := [["the three truths", "th"], ["ababababab", "abab"]];
loop for [s, subs] in tests do
print("'" + subs + "' in '" + s + "': "
+ str countSubs(s, subs));
end loop;
proc countSubs(s, subs);
count := 0;
loop while s(subs) /= om do
s(subs) := "";
count +:= 1;
end loop;
return count;
end proc;
end program;</syntaxhighlight>
{{out}}
<pre>'th' in 'the three truths': 3
'abab' in 'ababababab': 2</pre>
=={{header|SenseTalk}}==
'''Simply stated:'''
<syntaxhighlight lang="sensetalk">
put the number of occurrences of "th" in "the three truths" --> 3
put the number of occurrences of "abab" in "ababababab" -- > 2
</syntaxhighlight>
'''User-created function:'''
<syntaxhighlight lang="sensetalk">
put countSubstring("aaaaa","a") // 5
put countSubstring("abababa","aba") // 2
function countSubstring mainString, subString
return number of occurrences of subString in mainString
end countSubstring
</syntaxhighlight>
=={{header|Sidef}}==
'''Built-in:'''
<syntaxhighlight lang="ruby">say "the three truths".count("th");
say "ababababab".count("abab");</syntaxhighlight>
'''User-created function:'''
<syntaxhighlight lang="ruby">func countSubstring(s, ss) {
var re = Regex.new(ss.escape, 'g'); # 'g' for global
var counter = 0;
while (s =~ re) { ++counter };
return counter;
}
say countSubstring("the three truths","th");
say countSubstring("ababababab","abab");</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Simula}}==
<syntaxhighlight lang="simula">BEGIN
INTEGER PROCEDURE COUNTSUBSTRING(T,TSUB); TEXT T,TSUB;
BEGIN
INTEGER N,I;
I := 1;
WHILE I+TSUB.LENGTH-1 <= T.LENGTH DO
IF T.SUB(I,TSUB.LENGTH) = TSUB THEN
BEGIN
N := N+1;
I := I+MAX(TSUB.LENGTH,1);
END ELSE I := I+1;
COUNTSUBSTRING:= N;
END COUNTSUBSTRING;
OUTINT(COUNTSUBSTRING("THE THREE TRUTHS", "TH"),0);
OUTIMAGE;
OUTINT(COUNTSUBSTRING("ABABABABAB", "ABAB"),0);
OUTIMAGE;
END.</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Smalltalk}}==
{{works with|Smalltalk/X}}
<syntaxhighlight lang="smalltalk">Transcript showCR:('the three truths' occurrencesOfString:'th').
Transcript showCR:('ababababab' occurrencesOfString:'abab')</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|SNOBOL4}}==
<syntaxhighlight lang="snobol4">
DEFINE("countSubstring(t,s)")
OUTPUT = countSubstring("the three truths","th")
OUTPUT = countSubstring("ababababab","abab")
:(END)
countSubstring t ARB s = :F(RETURN)
countSubstring = countSubstring + 1 :(countSubstring)
END
3
2
</syntaxhighlight>
=={{header|Standard ML}}==
<syntaxhighlight lang="sml">fun count_substrings (str, sub) =
let
fun aux (str', count) =
let
val suff = #2 (Substring.position sub str')
in
if Substring.isEmpty suff then
count
else
aux (Substring.triml (size sub) suff, count + 1)
end
in
aux (Substring.full str, 0)
end;
print (Int.toString (count_substrings ("the three truths", "th")) ^ "\n");
print (Int.toString (count_substrings ("ababababab", "abab")) ^ "\n");
print (Int.toString (count_substrings ("abaabba*bbaba*bbab", "a*b")) ^ "\n");</syntaxhighlight>
=={{header|Stata}}==
<syntaxhighlight lang="stata">function strcount(s, x) {
n = 0
k = 1-(i=strlen(x))
do {
if (k = ustrpos(s, x, k+i)) n++
} while(k)
return(n)
}
strcount("peter piper picked a peck of pickled peppers", "pe")
5
strcount("ababababab","abab")
2</syntaxhighlight>
=={{header|Swift}}==
<syntaxhighlight lang="swift">import Foundation
func countSubstring(str: String, substring: String) -> Int {
return str.components(separatedBy: substring).count - 1
}
print(countSubstring(str: "the three truths", substring: "th"))
print(countSubstring(str: "ababababab", substring: "abab"))</syntaxhighlight>
{{out}}
<pre>3
2</pre>
=={{header|Tcl}}==
The regular expression engine is ideal for this task, especially as the <tt>***=</tt> prefix makes it interpret the rest of the argument as a literal string to match:
<
regexp -all ***=$needle $haystack
}
puts [countSubstrings "the three truths" "th"]
puts [countSubstrings "ababababab" "abab"]
puts [countSubstrings "abaabba*bbaba*bbab" "a*b"]</
{{out}}
<pre>3
2
2</pre>
=={{header|Transd}}==
<syntaxhighlight lang="scheme">#lang transd
MainModule: {
countSubstring: (λ s String() sub String()
(with n 0 pl 0
(while (> (= pl (find s sub pl)) -1)
(+= pl (size sub)) (+= n 1))
(lout n))
),
_start: (λ
(countSubstring "the three truths" "th")
(countSubstring "ababababab" "abab")
)
}</syntaxhighlight>{{out}}
<pre>
3
2
</pre>
=={{header|TUSCRIPT}}==
<syntaxhighlight lang="tuscript">
$$ MODE TUSCRIPT, {}
occurences=COUNT ("the three truths", ":th:")
occurences=COUNT ("ababababab", ":abab:")
occurences=COUNT ("abaabba*bbaba*bbab",":a\*b:")
</syntaxhighlight>
{{out}}
<pre>
3
2
2
</pre>
=={{header|TXR}}==
<syntaxhighlight lang="txr">@(next :args)
@(do (defun count-occurrences (haystack needle)
(for* ((occurrences 0)
(old-pos 0)
(new-pos (search-str haystack needle old-pos nil)))
(new-pos occurrences)
((inc occurrences)
(set old-pos (+ new-pos (length needle)))
(set new-pos (search-str haystack needle old-pos nil))))))
@ndl
@hay
@(output)
@(count-occurrences hay ndl) occurrences(s) of @ndl inside @hay
@(end)</syntaxhighlight>
<pre>$ ./txr count-occurrences.txr "baba" "babababa"
2 occurence(s) of baba inside babababa
$ ./txr count-occurrences.txr "cat" "catapultcatalog"
2 occurence(s) of cat inside catapultcatalog</pre>
=={{header|UNIX Shell}}==
{{works with|Bash}}
<syntaxhighlight lang="bash">#!/bin/bash
function countString(){
input=$1
cnt=0
until [ "${input/$2/}" == "$input" ]; do
input=${input/$2/}
let cnt+=1
done
echo $cnt
}
countString "the three truths" "th"
countString "ababababab" "abab"</syntaxhighlight>
{{Out}}
<pre>3
2</pre>
=={{header|VBA}}==
<syntaxhighlight lang="vba">Function CountStringInString(stLookIn As String, stLookFor As String)
CountStringInString = UBound(Split(stLookIn, stLookFor))
End Function</syntaxhighlight>
=={{header|VBScript}}==
'''user created function'''
<syntaxhighlight lang="vb">
Function CountSubstring(str,substr)
CountSubstring = 0
For i = 1 To Len(str)
If Len(str) >= Len(substr) Then
If InStr(i,str,substr) Then
CountSubstring = CountSubstring + 1
i = InStr(i,str,substr) + Len(substr) - 1
End If
Else
Exit For
End If
Next
End Function
WScript.StdOut.Write CountSubstring("the three truths","th") & vbCrLf
WScript.StdOut.Write CountSubstring("ababababab","abab") & vbCrLf
</syntaxhighlight>
'''Using built-in Regexp'''
Run it with CScript.
<syntaxhighlight lang="vb">
function CountSubstring(str,substr)
with new regexp
.pattern=substr
.global=true
set m=.execute(str)
end with
CountSubstring =m.count
end function
WScript.StdOut.Writeline CountSubstring("the three truths","th")
WScript.StdOut.Writeline CountSubstring("ababababab","abab")
</syntaxhighlight>
{{Out}}
<pre>
3
2
</pre>
=={{header|Visual Basic .NET}}==
<syntaxhighlight lang="vbnet">Module Count_Occurrences_of_a_Substring
Sub Main()
Console.WriteLine(CountSubstring("the three truths", "th"))
Console.WriteLine(CountSubstring("ababababab", "abab"))
Console.WriteLine(CountSubstring("abaabba*bbaba*bbab", "a*b"))
Console.WriteLine(CountSubstring("abc", ""))
End Sub
Function CountSubstring(str As String, substr As String) As Integer
Dim count As Integer = 0
If (Len(str) > 0) And (Len(substr) > 0) Then
Dim p As Integer = InStr(str, substr)
Do While p <> 0
p = InStr(p + Len(substr), str, substr)
count += 1
Loop
End If
Return count
End Function
End Module</syntaxhighlight>
{{Out}}
<pre>3
2
2
0</pre>
=={{header|V (Vlang)}}==
<syntaxhighlight lang="v (vlang)">fn main(){
println('the three truths'.count('th'))
println('ababababab'.count('abab'))
}</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
=={{header|Wortel}}==
<syntaxhighlight lang="wortel">@let {
c &[s t] #!s.match &(t)g
[[
!!c "the three truths" "th"
!!c "ababababab" "abab"
]]
}</syntaxhighlight>
Returns: <pre>[3 2]</pre>
=={{header|Wren}}==
{{libheader|Wren-pattern}}
{{libheader|Wren-fmt}}
<syntaxhighlight lang="wren">import "./pattern" for Pattern
import "./fmt" for Fmt
var countSubstring = Fn.new { |str, sub|
var p = Pattern.new(sub)
return p.findAll(str).count
}
var tests = [
["the three truths", "th"],
["ababababab", "abab"],
["abaabba*bbaba*bbab", "a*b"],
["aaaaaaaaaaaaaa", "aa"],
["aaaaaaaaaaaaaa", "b"],
]
for (test in tests) {
var count = countSubstring.call(test[0], test[1])
Fmt.print("$6s occurs $d times in $q.", Fmt.q(test[1]), count, test[0])
}</syntaxhighlight>
{{out}}
<pre>
"th" occurs 3 times in "the three truths".
"abab" occurs 2 times in "ababababab".
"a*b" occurs 2 times in "abaabba*bbaba*bbab".
"aa" occurs 7 times in "aaaaaaaaaaaaaa".
"b" occurs 0 times in "aaaaaaaaaaaaaa".
</pre>
Alternatively, using a library method (output same as before):
{{libheader|Wren-str}}
<syntaxhighlight lang="wren">import "./str" for Str
import "./fmt" for Fmt
var tests = [
["the three truths", "th"],
["ababababab", "abab"],
["abaabba*bbaba*bbab", "a*b"],
["aaaaaaaaaaaaaa", "aa"],
["aaaaaaaaaaaaaa", "b"],
]
for (test in tests) {
var count = Str.occurs(test[0], test[1])
Fmt.print("$6s occurs $d times in $q.", Fmt.q(test[1]), count, test[0])
}</syntaxhighlight>
=={{header|XPL0}}==
<syntaxhighlight lang="xpl0">include c:\cxpl\codes; \intrinsic 'code' declarations
string 0; \use zero-terminated strings, instead of MSb terminated
func StrNCmp(A, B, N); \Compare string A to string B up to N bytes long
\This returns:
\ >0 if A > B
\ =0 if A = B
\ <0 if A < B
char A, B; \strings to be compared
int N; \number of bytes to compare
int I;
[for I:= 0 to N-1 do
if A(I) # B(I) then
return A(I) - B(I);
return 0; \they're equal
]; \StrNCmp
func StrLen(Str); \Return the number of characters in an ASCIIZ string
char Str;
int I;
for I:= 0 to -1>>1-1 do
if Str(I) = 0 then return I;
func SubStr(A, B); \Count number of times string B occurs in A
char A, B;
int LA, LB, C, I;
[LA:= StrLen(A); LB:= StrLen(B);
C:= 0; I:= 0;
while I < LA do
if StrNCmp(B, A+I, LB) = 0 then [C:= C+1; I:= I+LB]
else I:= I+1;
return C;
];
[IntOut(0, SubStr("the three truths", "th")); CrLf(0);
IntOut(0, SubStr("ababababab", "abab")); CrLf(0);
]</syntaxhighlight>
{{out}}
<pre>
3
2
</pre>
<pre>
>> % Count occurrences of a substring without overlap
>> length(findstr("ababababab","abab",0))
ans = 2
>> length(findstr("the three truths","th",0))
ans = 3
>> % Count occurrences of a substring with overlap
>> length(findstr("ababababab","abab",1))
ans = 4
>>
</pre>
=={{header|zkl}}==
Two solutions:
<syntaxhighlight lang="zkl">fcn countSubstring(s,p){ pn:=p.len(); cnt:=n:=0;
while(Void!=(n:=s.find(p,n))){cnt+=1; n+=pn}
cnt
}</syntaxhighlight>
{{trans|J}}
<syntaxhighlight lang="zkl">fcn countSubstring(s,p){ (pl:=p.len()) and (s.len()-(s-p).len())/pl }</syntaxhighlight>
{{out}}
<pre>
zkl: println(countSubstring("the three truths","th"))
3
zkl: println(countSubstring("ababababab","abab"))
2
zkl: println(countSubstring("ababababab","v"))
0
</pre>
=={{header|ZX Spectrum Basic}}==
<syntaxhighlight lang="zxbasic">10 LET t$="ABABABABAB": LET p$="ABAB": GO SUB 1000
20 LET t$="THE THREE TRUTHS": LET p$="TH": GO SUB 1000
30 STOP
1000 PRINT t$: LET c=0
1010 LET lp=LEN p$
1020 FOR i=1 TO LEN t$-lp+1
1030 IF (t$(i TO i+lp-1)=p$) THEN LET c=c+1: LET i=i+lp-1
1040 NEXT i
1050 PRINT p$;"=";c''
1060 RETURN </syntaxhighlight>
| |||