Strip a set of characters from a string
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:
You are encouraged to solve this task according to the task description, using any language you may know.
<lang pseudocode> print stripchars("She was a soul stripper. She took my heart!","aei") Sh ws soul strppr. Sh took my hrt!</lang>
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 ||:= 2(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>
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!"
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!"
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> Sample output:
Sh ws soul strppr. Sh took my hrt!
Python
<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>
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>