Faster JavaScript Trim

Posted by Luca on May 28th, 2008 in Javascript.

I've recently discovered the very interesting Steven Levithan post about the JavaScript's trim function of the String class.

So, here my version:

   1  function trim13 (str) {
   2    var ws = /\s/, _start = 0, end = str.length;
   3    while(ws.test(str.charAt(_start++)));
   4    while(ws.test(str.charAt(--end)));
   5    return str.slice(_start - 1, end + 1);
   6  }

More numbers, please!

I tested my function against the benchmarking page of the original post.
Note: times are expressed in MS and are the average of ten executions per browser.
Update [2008-05-29]: I re-runned all the tests and updated results, because Steven noticed that test suite was wrong (few whitespaces).

Mac Windows
Safari 3.1 Firefox 2.0.0.14 Firefox 3.0b5 Opera 9.27 Opera 9.50b2 Internet Explorer 6 Internet Explorer 7 Firefox 2.0.0.14 Opera 9.27 Opera 9.50b2 Average
trim1 25 40 19 100 93 12 12 38 124 111 57
trim2 25 52 29 100 98 6 11 44 125 116 61
trim3 32 54 46 156 148 15 31 57 209 184 93
trim4 43 43 37 151 139 15 38 49 198 186 90
trim5 64 102 104 134 116 65 908 323 291 274 238
trim6 69 115 109 195 171 47 1.497 364 436 338 334
trim7 69 120 107 142 129 31 900 345 330 271 244
trim8 4 118 104 112 97 4 5 540 255 180 142
trim9 34 126 116 1.825 1.218 23 74 113 1.667 1.417 662
trim10 0 1 6 5 3 2 1 0 6 0 2
trim11 2 2 3 11 3 2 2 10 5 7 5
trim12 1 3 2 4 6 1 2 10 4 4 4
trim13 0 0 3 1 1 0 1 2 0 5 1

Please download the benchmark suite, and test against your browsers.

Tags:

  • facebook
  • twitter
  • digg
  • delicious
  • stumbleupon

advertising

Comments

  1. Steve's Gravatar

    Posted by Steve on 2008-05-28 22:41:59 UTC (permalink)

    Hi Luca, great list of tested browsers! I don't have a Mac at my disposal, so those test results are particularly interesting for me.

    I've noted a potential issue with your implementation over on my blog at http://blog.stevenlevithan.com/archives/faster-trim-javascript#comment-21445 . Also, as noted there, you can't accurately claim that an implementation is the fastest unless that holds true with any subject data.

  2. jx's Gravatar

    Posted by jx on 2008-06-14 15:13:13 UTC (permalink)

    a little change:

    function trim13 (str) {
    var ws = /\s/, _start = 0, _end = str.length-1;

    while(ws.test(str.charAt(_start))) _start++;
    if( _start > _end) return '';

    while(ws.test(str.charAt(_end))) _end--;
    return str.slice(_start , _end );
    }

  3. jx's Gravatar

    Posted by jx on 2008-06-14 15:40:38 UTC (permalink)

    function trim13 (str) {
    var ws = /\s/, _start = -1, _end = str.length;
    while(ws.test(str.charAt(++_start)));
    if( _start >= _end) return '';
    while(ws.test(str.charAt(--_end)));
    return str.slice(_start , _end);
    }