Strip a set of characters from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to create a function that strips a set of characters from a string. The function should take two arguments: the first argument being a string to stripped and the second, a string containing the set of characters to be stripped. The returned string should contain the first string, stripped of any characters in the second argument:
<lang pseudocode> print stripchars("She was a soul stripper. She took my heart!","aei") Sh ws soul strppr. Sh took my hrt!</lang>
Ada
<lang Ada>with Ada.Text_IO;
procedure Strip_Characters_From_String is
function Strip(The_String: String; The_Characters: String) return String is Keep: array (Character) of Boolean := (others => True); Result: String(The_String'Range); Last: Natural := Result'First-1; begin for I in The_Characters'Range loop Keep(The_Characters(I)) := False; end loop; for J in The_String'Range loop if Keep(The_String(J)) then Last := Last+1; Result(Last) := The_String(J); end if; end loop; return Result(Result'First .. Last); end Strip;
S: String := "She was a soul stripper. She took my heart!";
begin -- main
Ada.Text_IO.Put_Line(Strip(S, "aei"));
end Strip_Characters_From_String;</lang>
- Output:
> ./strip_characters_from_string Sh ws soul strppr. Sh took my hrt!
Aime
<lang aime>text stripchars1(text s, text w) {
integer p; data b;
b_cast(b, s); p = b_look(b, 0, w); while (p < b_length(b)) { b_delete(b, p); p += b_look(b, p, w); }
return b_string(b);
}
text stripchars2(text s, text w) {
data b;
b_cast(b, s); b_drop(b, w);
return b_string(b);
}
integer main(void) {
o_text(stripchars1("She was a soul stripper. She took my heart!", "aei")); o_newline();
o_text(stripchars2("She was a soul stripper. She took my heart!", "aei")); o_newline();
return 0;
}</lang>
ALGOL 68
<lang algol68>#!/usr/local/bin/a68g --script #
PROC strip chars = (STRING mine, ore)STRING: (
STRING out := ""; FOR i FROM LWB mine TO UPB mine DO IF NOT char in string(mine[i], LOC INT, ore) THEN out +:= mine[i] FI OD; out[@LWB mine]
);
printf(($gl$,stripchars("She was a soul stripper. She took my heart!","aei")))</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Applesoft BASIC
<lang basic>100 LET S$ = "SHE WAS A SOUL STRIPPER. SHE TOOK MY HEART!" 110 LET RM$ = "AEI" 120 GOSUB 200STRIPCHARS 130 PRINT SC$ 190 END 200 REM 210 REM STRIPCHARS 220 REM 230 LET SC$ = "" 240 LET SL = LEN (S$) 250 IF SL = 0 THEN RETURN 260 FOR SI = 1 TO SL 270 LET SM$ = MID$ (S$,SI,1) 280 FOR SJ = 1 TO LEN (RM$) 290 LET SR$ = MID$ (RM$,SJ,1) 300 LET ST = SR$ < > SM$ 310 IF ST THEN NEXT SJ 320 IF ST THEN SC$ = SC$ + SM$ 330 NEXT SI 340 RETURN </lang>
- Output:
SH WS SOUL STRPPR. SH TOOK MY HRT!
AutoHotkey
<lang AutoHotkey>MsgBox % stripchars("She was a soul stripper. She took my heart!","aei")
StripChars(string, charsToStrip){
Loop Parse, charsToStrip StringReplace, string, string, % A_LoopField, , All return string
}</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
AWK
<lang AWK>#!/usr/bin/awk -f BEGIN {
x = "She was a soul stripper. She took my heart!"; print x; gsub(/[aei]/,"",x); print x;
}</lang>
- Output:
She was a soul stripper. She took my heart! Sh ws soul strppr. Sh took my hrt!
BASIC
<lang qbasic>DECLARE FUNCTION stripchars$(src AS STRING, remove AS STRING)
PRINT stripchars$("She was a soul stripper. She took my heart!", "aei")
FUNCTION stripchars$(src AS STRING, remove AS STRING)
DIM l0 AS LONG, t AS LONG, s AS STRING s = src FOR l0 = 1 TO LEN(remove) DO t = INSTR(s, MID$(remove, l0, 1)) IF t THEN s = LEFT$(s, t - 1) + MID$(s, t + 1) ELSE EXIT DO END IF LOOP NEXT stripchars$ = s
END FUNCTION</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
See also: Liberty BASIC, PureBasic
BBC BASIC
<lang bbcbasic> PRINT FNstripchars("She was a soul stripper. She took my heart!", "aei")
END DEF FNstripchars(A$, S$) LOCAL I%, C%, C$ FOR I% = 1 TO LEN(S$) C$ = MID$(S$, I%, 1) REPEAT C% = INSTR(A$, C$) IF C% A$ = LEFT$(A$, C%-1) + MID$(A$, C%+1) UNTIL C% = 0 NEXT = A$</lang>
Output:
Sh ws soul strppr. Sh took my hrt!
Bracmat
This solution handles Unicode (utf-8) characters. Optimizations are: (1) the chars
string is hard-coded into the pattern before the pattern is used in the match expression, (2) the output characters are stacked (cheap) rather than appended (expensive). The result string is obtained by stringizing the stack and reversing. To make multibyte characters survive, they are reversed before being put onto the stack. A problem is that this code is negligent of diacritical marks.
<lang bracmat>( ( strip
= string chars s pat . !arg:(?string.?chars) & :?s & ' ( ? ( % : [%( utf$!sjt & ( @($chars:? !sjt ?) | rev$!sjt !s:?s ) & ~ ) ) ? ) : (=?pat) & @(!string:!pat) | rev$(str$!s) )
& out
$ (strip$("Аппетит приходит во время еды".веп)
);</lang>
- Output:
Атит риходит о рмя ды
Burlesque
<lang burlesque> blsq ) "She was a soul stripper. She took my heart!"{"aei"\/~[n!}f[ "Sh ws soul strppr. Sh took my hrt!" </lang>
C
<lang c>#include <string.h>
- include <stdio.h>
- include <stdlib.h>
/* removes all chars from string */
char *strip_chars(const char *string, const char *chars) {
char * newstr = malloc(strlen(string) + 1); int counter = 0;
for ( ; *string; string++) { if (!strchr(chars, *string)) { newstr[ counter ] = *string; ++ counter; } }
newstr[counter] = 0; return newstr;
}
int main(void) {
char *new = strip_chars("She was a soul stripper. She took my heart!", "aei"); printf("%s\n", new);
free(new); return 0;
}</lang>
- Result:
Sh ws soul strppr. Sh took my hrt!
With table lookup
<lang C>#include <stdio.h>
- include <stdlib.h>
- include <string.h>
char *strip(const char * str, const char *pat) { /* char replacement is typically done with lookup tables if * the replacement set can be large: it turns O(m n) into * O(m + n). * If same replacement pattern is going to be applied to many * strings, it's better to build a table beforehand and reuse it. * If charset is big like unicode, table needs to be implemented * more efficiently, say using bit field or hash table -- it * all depends on the application. */ int i = 0, tbl[128] = {0}; while (*pat != '\0') tbl[(int)*(pat++)] = 1;
char *ret = malloc(strlen(str) + 1); do { if (!tbl[(int)*str]) ret[i++] = *str; } while (*(str++) != '\0');
/* assuming realloc is efficient and succeeds; if not, we could * do a two-pass, count first, alloc and strip second */ return realloc(ret, i); }
int main() { char * x = strip("She was a soul stripper. She took my heart!", "aei"); printf(x); free(x);
return 0; }</lang>Output same as above.
C++
<lang cpp>#include <algorithm>
- include <iostream>
- include <string>
std::string stripchars(std::string str, const std::string &chars) {
str.erase( std::remove_if(str.begin(), str.end(), [&](char c){ return chars.find(c) != std::string::npos; }), str.end() ); return str;
}
int main() {
std::cout << stripchars("She was a soul stripper. She took my heart!", "aei") << '\n'; return 0;
}</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
C#
<lang csharp>using System;
public static string RemoveCharactersFromString(string testString, string removeChars) {
char[] charAry = removeChars.ToCharArray(); string returnString = testString; foreach (char c in charAry) { while (returnString.IndexOf(c) > -1) { returnString = returnString.Remove(returnString.IndexOf(c), 1); } } return returnString;
}</lang> Usage: <lang C sharp> using System;
class Program {
static void Main(string[] args) { string testString = "She was a soul stripper. She took my heart!"; string removeChars = "aei"; Console.WriteLine(RemoveCharactersFromString(testString, removeChars)); }
} </lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Using Regex
:
<lang C sharp>
using System;
using System.Text.RegularExpressions;
private static string RegexRemoveCharactersFromString(string testString, string removeChars) {
string pattern = "[" + removeChars + "]"; return Regex.Replace(testString, pattern, "");
}</lang>
Clojure
<lang Clojure>(defn strip [coll chars]
(apply str (remove #((set chars) %) coll)))
(strip "She was a soul stripper. She took my heart!" "aei")
- => "Sh ws soul strppr. Sh took my hrt!"</lang>
COBOL
This function takes the two arguments as specified in the task. However, the result will be returned in the string that had the characters stripped from it, and the string containing the characters to strip must be null-terminated (otherwise, a table would have to be used instead). <lang cobol> IDENTIFICATION DIVISION.
PROGRAM-ID. Strip-Chars.
DATA DIVISION. WORKING-STORAGE SECTION. 01 Str-Size CONSTANT 128.
LOCAL-STORAGE SECTION. 01 I PIC 999. 01 Str-Pos PIC 999.
01 Offset PIC 999. 01 New-Pos PIC 999.
01 Str-End PIC 999.
LINKAGE SECTION. 01 Str PIC X(Str-Size). 01 Chars-To-Replace PIC X(256).
PROCEDURE DIVISION USING Str BY VALUE Chars-To-Replace. Main. PERFORM VARYING I FROM 1 BY 1 UNTIL Chars-To-Replace (I:1) = X"00"
MOVE ZERO TO Offset
- *> Overwrite the characters to remove by left-shifting
- *> following characters over them.
PERFORM VARYING Str-Pos FROM 1 BY 1 UNTIL Str-Size < Str-Pos IF Str (Str-Pos:1) = Chars-To-Replace (I:1) ADD 1 TO Offset ELSE IF Offset NOT = ZERO COMPUTE New-Pos = Str-Pos - Offset MOVE Str (Str-Pos:1) TO Str (New-Pos:1) END-IF END-PERFORM
- *> Move spaces to characters at the end that have been
- *> shifted over.
COMPUTE Str-End = Str-Size - Offset MOVE SPACES TO Str (Str-End:Offset) END-PERFORM
GOBACK .</lang>
ColdFusion
<lang cfm> <Cfset theString = 'She was a soul stripper. She took my heart!'> <Cfset theStrip = 'aei'> <Cfloop from="1" to="#len(theStrip)#" index="i">
<cfset theString = replace(theString, Mid(theStrip, i, 1), , 'all')>
</Cfloop> <Cfoutput>#theString#</Cfoutput> </lang>
Common Lisp
<lang lisp>(defun strip-chars (str chars)
(remove-if (lambda (ch) (find ch chars)) str))
(strip-chars "She was a soul stripper. She took my heart!" "aei")
- => "Sh ws soul strppr. Sh took my hrt!"</lang>
D
<lang d>import std.stdio, std.string;
void main() {
auto s = "She was a soul stripper. She took my heart!"; auto ss = "Sh ws soul strppr. Sh took my hrt!"; assert(s.removechars("aei") == ss);
}</lang>
Delphi
<lang Delphi>program StripCharacters;
{$APPTYPE CONSOLE}
uses SysUtils;
function StripChars(const aSrc, aCharsToStrip: string): string; var
c: Char;
begin
Result := aSrc; for c in aCharsToStrip do Result := StringReplace(Result, c, , [rfReplaceAll, rfIgnoreCase]);
end;
const
TEST_STRING = 'She was a soul stripper. She took my heart!';
begin
Writeln(TEST_STRING); Writeln(StripChars(TEST_STRING, 'aei'));
end.</lang>
Elixir
The easiest solution would be to use replace from the String module, which takes a Regex. <lang elixir> str = "She was a soul stripper. She took my heart!" String.replace(str, ~r/a|e|i/, "")
- => Sh ws soul strppr. Sh took my hrt!
</lang> To get the desired interface, we just have to dynamically construct the Regex: <lang elixir> defmodule RC do
def stripchars(str, chars) do String.replace(str, ~r/#{Enum.join(String.split(chars, ""), "|")}/, "") end
end
str = "She was a soul stripper. She took my heart!"
RC.stripchars(str, "aei")
- => Sh ws soul strppr. Sh took my hrt!
</lang>
Erlang
The function is created in the shell. A module would be over engineering.
- Output:
4> F = fun(To_stripp, Strip_with) -> lists:filter( fun(C) -> not lists:member(C, Strip_with) end, To_stripp ) end. #Fun<erl_eval.12.111823515> 5> F("She was a soul stripper. She took my heart!", "aei"). "Sh ws soul strppr. Sh took my hrt!"
Euphoria
The includes use Euphoria 4 standard library files.
A sequence called originalString holds the text to be converted.
The puts
function is for console output.
The work of this task is done by the transmute
function; this function takes parameters separated by commas. Here it uses 3 parameters, up to 5, the other two are optional and aren't put in this time.
The transmute
function's usage and examples can be searched for in the official Euphoria 4.0.0+ manual. Euphoria object identifiers (names) are case sensitive but don't need to be in a particular case to be recognized as an object type.
<lang euphoria>include std\sequence.e
include std\console.e
sequence originalString = "She was a soul stripper. She took my heart!" puts(1,"Before : " & originalString & "\n") originalString = transmute(originalString, {{} , "a", "e", "i"}, {{} , "", "", ""}) puts(1,"After : " & originalString & "\n") any_key()</lang>
- Output:
Before : She was a soul stripper. She took my heart! After : Sh ws soul strppr. Sh took my hrt! Press Any Key to continue...
F#
<lang fsharp>let stripChars text (chars:string) =
Array.fold ( fun (s:string) c -> s.Replace(c.ToString(),"") ) text (chars.ToCharArray())
[<EntryPoint>] let main args =
printfn "%s" (stripChars "She was a soul stripper. She took my heart!" "aei") 0</lang>
Output
Sh ws soul strppr. Sh took my hrt!
Fortran
<lang Fortran>elemental subroutine strip(string,set)
character(len=*), intent(inout) :: string character(len=*), intent(in) :: set integer :: old, new, stride old = 1; new = 1 do stride = scan( string( old : ), set ) if ( stride > 0 ) then string( new : new+stride-2 ) = string( old : old+stride-2 ) old = old+stride new = new+stride-1 else string( new : ) = string( old : ) return end if end do
end subroutine strip</lang>Note: Since strip is an elemental subroutine, it can be called with arrays of strings as well.
Go
<lang go>package main
import (
"fmt" "strings"
)
func stripchars(str, chr string) string {
return strings.Map(func(r rune) rune { if strings.IndexRune(chr, r) < 0 { return r } return -1 }, str)
}
func main() {
fmt.Println(stripchars("She was a soul stripper. She took my heart!", "aei"))
}</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Groovy
Solution: <lang groovy>def stripChars = { string, stripChars ->
def list = string as List list.removeAll(stripChars as List) list.join()
}</lang> Test: <lang groovy>println (stripChars('She was a soul stripper. She took my heart!', 'aei'))</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Haskell
I decided to make the string the second argument and the characters the first argument, because it is more likely for someone to partially apply the characters to be stripped (making a function that strips certain characters), than the string. <lang haskell>stripChars :: String -> String -> String stripChars = filter . flip notElem</lang>
- Testing in GHCI:
> stripChars "aei" "She was a soul stripper. She took my heart!" "Sh ws soul strppr. Sh took my hrt!"
Icon and Unicon
The following works in both languages: <lang unicon>procedure main(A)
cs := \A[1] | 'aei' # argument is set of characters to strip every write(stripChars(!&input, cs)) # strip all input lines
end
procedure stripChars(s,cs)
ns := "" s ? while ns ||:= (not pos(0), tab(upto(cs)|0)) do tab(many(cs))) return ns
end</lang>
- Sample runs:
->strip She was a soul stripper. She took my heart! Sh ws soul strppr. Sh took my hrt! Aardvarks are ant eaters. Ardvrks r nt trs. ->strip AEIOUaeiou Aardvarks are ant eaters. rdvrks r nt trs. ->
J
Solution:
The dyadic primitive -.
(Less) is probably the simplest way to solve this task.
- Example Usage:
<lang j> 'She was a soul stripper. She took my heart!' -. 'aei' Sh ws soul strppr. Sh took my hrt!</lang>
Java
<lang Java>class StripChars {
public static String stripChars(String inString, String toStrip) { return inString.replaceAll("[" + toStrip + "]", ""); }
public static void main(String[] args) { String sentence = "She was a soul stripper. She took my heart!"; String chars = "aei"; System.out.println("sentence: " + sentence); System.out.println("to strip: " + chars); System.out.println("stripped: " + stripChars(sentence, chars)); }
}</lang>
- Output:
sentence: She was a soul stripper. She took my heart! to strip: aei stripped: Sh ws soul strppr. Sh took my hrt!
JavaScript
<lang JavaScript>function stripchars(string, chars) {
return string.replace(RegExp('['+chars+']','g'), );
}</lang>
jq
<lang jq>def stripchars(string; banish):
(string | explode) - (banish | explode) | implode;</lang>
Note: In jq, it would be more idiomatic to define the function as a filter: <lang jq>def stripchars(banish):
explode - (banish | explode) | implode;</lang>
In this case, we would write:
"She was a soul stripper. She took my heart!" | stripchars("aei")
Julia
Julia's replace
function is quite flexible. It takes only a bit of a tweak to get the desired result.
<lang Julia>
function fullstrip(s::String, r::String)
replace(s, Set(r), "")
end
tests = "She was a soul stripper. She took my heart!" testr = "aei"
println(tests, " => ", fullstrip(tests, testr)) </lang>
- Output:
She was a soul stripper. She took my heart! => Sh ws soul strppr. Sh took my hrt!
Lasso
<lang Lasso>define stripper(in::string,destroy::string) => { with toremove in #destroy->values do => { #in->replace(#toremove,) } return #in } stripper('She was a soul stripper. She took my heart!','aei')</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Logo
<lang logo>to strip :string :chars
output filter [not substringp ? :chars] :string
end
print strip "She\ was\ a\ soul\ stripper.\ She\ took\ my\ heart! "aei
bye</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Lua
<lang lua> function stripchars(str, chrs)
local s = str:gsub("["..chrs.."]", ) return s
end
print( stripchars( "She was a soul stripper. She took my heart!", "aei" ) ) </lang>
Liberty BASIC
<lang lb>Print stripchars$("She was a soul stripper. She took my heart!", "aei", 1) End
Function stripchars$(strip$, chars$, num)
For i = 1 To Len(strip$) If Mid$(strip$, i, 1) <> Mid$(chars$, num, 1) Then stripchars$ = (stripchars$ + Mid$(strip$, i, 1)) End If Next i If (num <= Len(chars$)) Then stripchars$ = stripchars$(stripchars$, chars$, (num + 1))
End Function</lang>
Maple
<lang Maple>with(StringTools):
Remove(c->Has("aei",c), "She was a soul stripper. She took my heart!");</lang> Output:
"Sh ws soul strppr. Sh took my hrt!"
Mathematica
<lang Mathematica>stripchars[a_,b_]:=StringReplace[a,(#->"")&/@Characters[b]] stripchars["She was a soul stripper. She took my heart!","aei"] ->Sh ws soul strppr. Sh took my hrt!</lang>
MATLAB / Octave
<lang MATLAB> function str = stripchars(str, charlist)
charlist = unique(charlist); for k=1:length(charlist) str(str==charlist(k)) = []; end; end; </lang>
- Output:
>>stripchars('She was a soul stripper. She took my heart!','aei') ans = Sh ws soul strppr. Sh took my hrt!
Nemerle
<lang Nemerle>StripChars( text : string, remove : string ) : string {
def chuck = Explode(remove); Concat( "", Split(text, chuck))
}</lang>
NetRexx
<lang NetRexx>/* NetRexx */
options replace format comments java crossref savelog symbols
say stripchars("She was a soul stripper. She took my heart!", "aei")
return
method stripchars(haystack, chs) public static
loop c_ = 1 to chs.length needle = chs.substr(c_, 1) haystack = haystack.changestr(needle, ) end c_
return haystack</lang>
NewLISP
<lang NewLISP>(let (sentence "She was a soul stripper. She took my heart!")
(replace "[aei]" sentence "" 0))</lang>
Nim
<lang nim>import strutils
proc `$` (x: seq[string]): string =
result = x.join("")
echo(split("She was a soul stripper. She took my heart!", {'a','e','i'}).join(""))
- using the above proc to overload the toString operator `$` as an alternative to using join()
echo($split("She was a soul stripper. She took my heart!", {'a','e','i'}))</lang>
- Output:
Sh ws soul strppr. Sh took my hrt! Sh ws soul strppr. Sh took my hrt!
Objective-C
<lang objc>@interface NSString (StripCharacters) - (NSString *) stripCharactersInSet: (NSCharacterSet *) chars; @end
@implementation NSString (StripCharacters) - (NSString *) stripCharactersInSet: (NSCharacterSet *) chars {
return [[self componentsSeparatedByCharactersInSet:chars] componentsJoinedByString:@""];
} @end</lang>
- To use:
<lang objc> NSString *aString = @"She was a soul stripper. She took my heart!";
NSCharacterSet* chars = [NSCharacterSet characterSetWithCharactersInString:@"aei"];
// Display the NSString. NSLog(@"%@", [aString stripCharactersInSet:chars]);</lang>
OCaml
<lang ocaml>let stripchars s cs =
let len = String.length s in let res = String.create len in let rec aux i j = if i >= len then String.sub res 0 j else if String.contains cs s.[i] then aux (succ i) (j) else begin res.[j] <- s.[i]; aux (succ i) (succ j) end in aux 0 0</lang>
- Testing in the toplevel:
# stripchars "She was a soul stripper. She took my heart!" "aei" ;; - : string = "Sh ws soul strppr. Sh took my hrt!"
Oforth
<lang Oforth>String method: stripChars(str) { self filter(#[ str include not ]) }
"She was a soul stripper. She took my heart!" stripChars("aei") println</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
PARI/GP
GP should not be used for string manipulation. A good solution to this problem would probably involve system("perl -e
...
<lang parigp>stripchars(s, bad)={
bad=Set(Vec(Vecsmall(bad))); s=Vecsmall(s); my(v=[]); for(i=1,#s,if(!setsearch(bad,s[i]),v=concat(v,s[i]))); Strchr(v)
}; stripchars("She was a soul stripper. She took my heart!","aei")</lang>
Pascal
See Delphi
Perl
Note: this example uses a regular expression character class. Certain characters, like hyphens and brackets, may need to be escaped. <lang perl>sub stripchars {
my ($s, $chars) = @_; $s =~ s/[$chars]//g; return $s;
}
print stripchars("She was a soul stripper. She took my heart!", "aei"), "\n";</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Another good option for stripping characters is to use the tr///
operator. This option is very efficient when the set of characters to strip is fixed at compile time, because tr///
is specifically designed for transforming and deleting characters. Note that hyphens also have special meaning in this case.
<lang perl>$str =~ tr/aei//d;</lang>
Since the characters used for tr///
must be fixed at compile time, unfortunately, it requires the use of an eval
to do this generally for any set of characters provided at runtime:
<lang perl>sub stripchars {
my ($s, $chars) = @_; eval("\$s =~ tr/$chars//d;"); return $s;
}</lang>
Perl 6
<lang perl6>sub strip_chars ( $s, $chars ) {
return $s.trans( $chars.comb X=> );
}
say strip_chars( 'She was a soul stripper. She took my heart!', 'aei' );</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
PHP
<lang php><?php function stripchars($s, $chars) {
return str_replace(str_split($chars), "", $s);
}
echo stripchars("She was a soul stripper. She took my heart!", "aei"), "\n"; ?></lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
PicoLisp
<lang PicoLisp>(de strDiff (Str1 Str2)
(pack (diff (chop Str1) (chop Str2))) )</lang>
- Output:
: (strDiff "She was a soul stripper. She took my heart!" "aei") -> "Sh ws soul strppr. Sh took my hrt!"
PL/I
<lang PL/I>strip_chars: procedure (text, chars) returns (character (100) varying);
declare text character (*) varying, chars character (*) varying; declare out_text character (100); declare ch character (1); declare (i, j) fixed binary;
j = 0; do i = 1 to length(text); ch = substr(text, i, 1); if index(chars, ch) = 0 then do; j = j + 1; substr(out_text, j, 1) = ch; end; end; return (substr(out_text, 1, j) );
end strip_chars;</lang>
Prolog
Works with SWI-Prolog and module lambda.pl written by Ulrich Neumerkel found there http://www.complang.tuwien.ac.at/ulrich/Prolog-inedit/lambda.pl . <lang Prolog>:- use_module(library(lambda)).
stripchars(String, Exclude, Result) :- exclude(\X^(member(X, Exclude)), String, Result1), string_to_list(Result, Result1). </lang>
- Output:
?- stripchars("She was a soul stripper. She took my heart!","aei", R). R = "Sh ws soul strppr. Sh took my hrt!".
PureBasic
PureBasic uses a single (for ASCII) or a two-byte (for Unicode) null to signal the end of a string. Nulls are thus excluded from the allowable characters to strip as they can't be included in a PureBasic string. <lang PureBasic>Procedure.s stripChars(source.s, charsToStrip.s)
Protected i, *ptrChar.Character, length = Len(source), result.s *ptrChar = @source For i = 1 To length If Not FindString(charsToStrip, Chr(*ptrChar\c)) result + Chr(*ptrChar\c) EndIf *ptrChar + SizeOf(Character) Next ProcedureReturn result
EndProcedure
If OpenConsole()
PrintN(stripChars("She was a soul stripper. She took my heart!", "aei")) Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input() CloseConsole()
EndIf</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Python
Not using regular expressions
<lang python>>>> def stripchars(s, chars): ... return s.translate(None, chars) ... >>> stripchars("She was a soul stripper. She took my heart!", "aei") 'Sh ws soul strppr. Sh took my hrt!'</lang>
<lang python>>>> import string >>> def stripchars(s, chars): ... return s.translate(string.maketrans("", ""), chars) ... >>> stripchars("She was a soul stripper. She took my heart!", "aei") 'Sh ws soul strppr. Sh took my hrt!'</lang> Implemented manually: <lang python>>>> def stripchars(s, chars): ... return "".join(c for c in s if c not in chars) ... >>> stripchars("She was a soul stripper. She took my heart!", "aei") 'Sh ws soul strppr. Sh took my hrt!'</lang>
Using regular expressions
<lang python>>>> import re >>> def stripchars(s, chars): return re.sub('[%s]+' % re.escape(chars), , s)
>>> stripchars("She was a soul stripper. She took my heart!", "aei") 'Sh ws soul strppr. Sh took my hrt!' >>> </lang>
Racket
<lang Racket>
- lang racket
- Using list operations
(define (stripchars1 text chars)
(list->string (remove* (string->list chars) (string->list text))))
- Using a regexp
- => will be broken if chars have "-" or "]" or "\\"
(define (stripchars2 text chars)
(regexp-replace* (~a "[" chars "]+") text ""))
</lang>
REXX
version 1
In the REXX language, strip usually means to remove leading and/or trailing characters from a string (most often, blanks). <lang rexx>/*REXX program to remove a set of characters from a string (haystack). */ say stripChars('She was a soul stripper. She took my heart!', "iea") exit /*stick a fork in it, we're done.*/ /*───────────────────────────────────STRIPCHARS subroutine──────────────*/ stripChars: procedure; parse arg haystack, remove
do j=1 for length(remove) haystack=changestr(substr(remove,j,1), haystack, ) end /*j*/
return haystack</lang>
Some older REXXes don't have a changestr bif, so one is included here CHANGESTR.REX.
- Output:
Sh ws soul strppr. Sh took my hrt!
version 3
This works on all Rexxes.
(Except for R4 and ROO at the least, there may be others.)
<lang rexx>
/* REXX ***************************************************************
- If source and stripchars don't contain a hex 00 character, this works
- 06.07.2012 Walter Pachl
- 19.06.2013 -"- space(result,0) -> space(result,0,' ')
- space(result,0) removes WHITESPACE not only blanks
- /
Say 'Sh ws soul strppr. Sh took my hrt! -- expected' Say stripchars("She was a soul stripper. She took my heart!","aei") Exit stripchars: Parse Arg string,stripchars result=translate(string,'00'x,' ') /* turn blanks into '00'x */ result=translate(result,' ',stripchars) /* turn stripchars into ' ' */ result=space(result,0,' ') /* remove all blanks */ Return translate(result,' ','00'x) /* '00'x back to blanks */ </lang>
version 4
Another neat (?) one No x00 restriction and no changestr
<lang rexx> stripchars: Procedure
Parse Arg i,s /* get input and chars to be removed */ o= /* initialize result */ Do While i\== /* loop through input */ Parse Var i c +1 i /* get one character */ If pos(c,s)=0 Then /* it's not to be removed */ o=o||c /* append it to the result */ End Return o /* return the result */
</lang>
Ruby
<lang ruby>>> "She was a soul stripper. She took my heart!".delete("aei") => "Sh ws soul strppr. Sh took my hrt!"</lang>
SAS
This code will write the resulting string to the log: <lang SAS>%let string=She was a soul stripper. She took my heart!; %let chars=aei; %let stripped=%sysfunc(compress("&string","&chars")); %put &stripped;</lang>
Log: <lang SAS>Sh ws soul strppr. Sh took my hrt!</lang>
Scala
<lang scala>def stripChars(s:String, ch:String)= s filterNot (ch contains _)
stripChars("She was a soul stripper. She took my heart!", "aei") // => Sh ws soul strppr. Sh took my hrt!</lang>
ScriptBasic
<lang scriptbasic> str1 = "She was a soul stripper. She took my heart!" rmv = "aei" FOR i = 1 TO LEN(rmv)
str1 = REPLACE(str1, MID(rmv, i, 1), "")
NEXT PRINT str1,"\n" </lang>
Sed
Using echo and piping it through a sed filter: <lang bash>#!/bin/bash
strip_char() {
echo "$1" | sed "s/[$2]//g"
}</lang>
Seed7
<lang seed7>$ include "seed7_05.s7i";
const func string: stripchars (in string: mainStri, in string: charList) is func
result var string: strippedStri is ""; local var char: ch is ' '; begin strippedStri := mainStri; for ch range charList do strippedStri := replace(strippedStri, str(ch), ""); end for; end func;
const proc: main is func
begin writeln(stripchars("She was a soul stripper. She took my heart!", "aei")); end func;</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Standard ML
<lang sml>fun stripchars (string, chars) = let
fun aux c = if String.isSubstring (str c) chars then "" else str c
in
String.translate aux string
end</lang>
- Testing:
- stripchars ("She was a soul stripper. She took my heart!", "aei") ; val it = "Sh ws soul strppr. Sh took my hrt!" : string
Alternately: <lang sml>fun stripchars (string, chars) =
String.concat (String.tokens (fn c => String.isSubstring (str c) chars) string)</lang>
- Testing:
- stripchars ("She was a soul stripper. She took my heart!", "aei") ; val it = "Sh ws soul strppr. Sh took my hrt!" : string
Smalltalk
<lang smalltalk>| stripChars | stripChars := [ :string :chars | string reject: [ :c | chars includes: c ] ]. stripChars value: 'She was a soul stripper. She took my heart!' value: 'aei'.
"'Sh ws soul strppr. Sh took my hrt!'"</lang>
Swift
<lang swift>extension String {
func stripCharactersInSet(chars: [Character]) -> String { return String(seq: filter(self) {find(chars, $0) == nil}) }
}
let aString = "She was a soul stripper. She took my heart!" let chars: [Character] = ["a", "e", "i"]
println(aString.stripCharactersInSet(chars))</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Tcl
<lang tcl>proc stripchars {str chars} {
foreach c [split $chars ""] {set str [string map [list $c ""] $str]} return $str
}
set s "She was a soul stripper. She took my heart!" puts [stripchars $s "aei"]</lang>
TorqueScript
This uses a default function.
$string = "She was a soul stripper. She took my heart!"; $chars = "aei"; $newString = stripChars($string, $chars); echo($string); echo($newString);
Output:
She was a soul stripper. She took my heart! Sh ws soul strppr. Sh took my hrt!
TUSCRIPT
<lang tuscript> $$ MODE TUSCRIPT,{} string="She was a soul stripper. She took my heart!" stringstrip=EXCHANGE (string,"_[aei]__") print string print stringstrip </lang> Output:
She was a soul stripper. She took my heart! Sh ws soul strppr. Sh took my hrt!
TXR
This solution builds up a regular expression in a hygienic way from the set of characters given as a string.
The string is broken into a list, which is used to construct a regex abstract syntax tree for a character set match, using a Lisp quasiquote. This is fed to the regex compiler, which produces an executable machine that is then used with regsub
On the practical side, some basic structural pattern matching is used to process command line argument list.
Since the partial argument list (the arguments belonging to the TXR script) is a suffix of the full argument list (the complete arguments which include the invoking command and the script name), the classic Lisp function ldiff
comes in handy in obtaining just the prefix, for printing the usage:
<lang txr>@(do
(defun strip-chars (str set) (let* ((regex-ast ^(set ,*(list-str set))) (regex-obj (regex-compile regex-ast))) (regsub regex-obj "" str)))
(defun usage () (pprinl `usage: @{(ldiff *full-args* *args*) " "} <string> <set>`) (exit 1)) (tree-case *args* ((str set extra) (usage)) ((str set . junk) (pprinl (strip-chars str set))) (else (usage))))</lang>
- Output:
$ txr strip-chars-2.txr usage: txr strip-chars-2.txr <string> <set> $ txr strip-chars-2.txr "she was a soul stripper. she stole my heart." "aei" sh ws soul strppr. sh stol my hrt.
Now here is a rewrite of strip-chars
which just uses classic Lisp that has been generalized to work over strings, plus the do
syntax (a sibling of the op
operator) that provides syntactic sugar for a lambda function whose body is an operator or macro form.
<lang txr>(defun strip-chars (str set)
(mappend (do if (memq @1 set) (list @1)) str))</lang>
(do if (memq @1 set) (list @1))
is just (lambda (item) (if (memq item set) (list item)))
.
mappend
happily maps over strings and since the leftmost input sequence is a string, and the return values of the lambda are sequence of characters, mappend
produces a string.
UNIX Shell
One would normally do this using the standard tr(1) command:
<lang bash>strip_chars() {
echo "$1" | tr -d "$2"
}</lang> But it can also be accomplished with bash's built-in parameter expansions:
<lang bash>function strip_chars {
echo "${1//[$2]}"
}</lang> Test code: <lang bash> strip_chars "She was a soul stripper. She took my heart!" aei</lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
Ursala
Normally there's no need to define this operation because it's built in. <lang Ursala>strip = ~&j
- cast %s
test = strip('she was a soul stripper. she took my heart','aei')</lang>
- Output:
'sh ws soul strppr. sh took my hrt'
VBA
Pass the optional bSpace parameter True to replace stripped characters with spaces, otherwise replaced with null.
<lang vb>Function StripChars(stString As String, stStripChars As String, Optional bSpace As Boolean) Dim i As Integer, stReplace As String
If bSpace = True Then stReplace = " " Else stReplace = "" End If For i = 1 To Len(stStripChars) stString = Replace(stString, Mid(stStripChars, i, 1), stReplace) Next i StripChars = stString
End Function</lang>
- Output:
' with bSpace = True: Sh w s soul str pp r. Sh took my h rt! 'with bSpace = False / omitted: Sh ws soul strppr. Sh took my hrt!
VBScript
<lang vb> Function stripchars(s1,s2) For i = 1 To Len(s1) If InStr(s2,Mid(s1,i,1)) Then s1 = Replace(s1,Mid(s1,i,1),"") End If Next stripchars = s1 End Function
WScript.StdOut.Write stripchars("She was a soul stripper. She took my heart!","aei") </lang>
- Output:
Sh ws soul strppr. Sh took my hrt!
zkl
<lang zkl>println("She was a soul stripper. She took my heart!"-"aei") //-->Sh ws soul strppr. Sh took my hrt!</lang>
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