Trim whitespace (spaces) from a string
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[edit] Implementations
[edit] PHP
$string = trim($string);
[edit] Java
The String class in Java has a built in trim function:
String s = " xyz ".trim(); System.out.println(s); // prints out "xyz";
[edit] JavaScript
Trim is not built into JavaScript, but you can use prototyping to add this to your code:
String.prototype.trim = function() {
return this.replace(/^\s+|\s+$/g,"");
}
Then you can use this code like this example:
var input = " xyz "; var output = input.trim(); // output = "xyz"
[edit] OCaml
let rec trim s = let l = String.length s in if l=0 then s else if s.[0]=' ' || s.[0]='\t' || s.[0]='\n' || s.[0]='\r' then trim (String.sub s 1 (l-1)) else if s.[l-1]=' ' || s.[l-1]='\t' || s.[l-1]='\n' || s.[l-1]='\r' then trim (String.sub s 0 (l-1)) else s
another solution:
let trim str =
if str = "" then "" else
let search_pos init p next =
let rec search i =
if p i then raise(Failure "empty") else
match str.[i] with
| ' ' | '\n' | '\r' | '\t' -> search (next i)
| _ -> i
in
search init
in
let len = String.length str in
try
let left = search_pos 0 (fun i -> i >= len) (succ)
and right = search_pos (len - 1) (fun i -> i < 0) (pred)
in
String.sub str left (right - left + 1)
with
| Failure "empty" -> ""
;;
[edit] Perl
s{\A\s*|\s*\z}{}gmsx; # remove leading and trailing whitespace
[edit] Python
Python strings have the strip(), lstrip(), rstrip() methods for removing any character from both ends of a string. If the characters to be removed are not specified then whitespace will be removed. strip() removes from both ends; lstrip() removes leading characters (Left-strip); rstrip() removes trailing characters (Right-strip).
" xyz ".strip() # returns "xyz"
" xyz ".lstrip() # returns "xyz "
" xyz ".rstrip() # returns " xyz"
" x y z ".replace(' ', '') # returns "xyz"
[edit] Ruby
This is very similar to the python version above.
irb(main):001:0> test = " test " => " test " irb(main):002:0> test.strip => "test" irb(main):003:0> test.lstrip => "test " irb(main):004:0> test.rstrip => " test"
[edit] Seed7
The trim function removes leading and trailing spaces and control chars:
writeln(trim(" xyz ")); # writes the string "xyz";
[edit] Visual Basic
To remove leading and/or trailing spaces from a string:
sString = LTrim(sString) ' Remove leading spaces' sString = RTrim(sString) ' Remove trailing spaces' sString = Trim(sString) ' Remove leading and trailing spaces'
To remove all spaces from a string:
sString = Replace(sString, " ", "")
[edit] Zsh
string=" 123 abc xyz "
${string// /} # output: 123abcxyz
