Info

Using try/catch inside of functions that allocate lots of variables introduces significant overhead. See this discussion related to node.js https://groups.google.com/forum/#!topic/nodejs-dev/E-Re9KDDo5w

Interestingly, other js engines don't have this overhead. All test runs have pretty uniform performance. But they are also significantly slower than the v8 control case.

Preparation code

<script>
  var tries = 10000;
  
  function test1() {
   function test(j) {
    var s = 0;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    return s;
   }
  
   test(tries);
  }
  
  function test2() {
   function test(j) {
    try {
     var s = 0;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     for (var i = 0; i < j; i++) s = i;
     return s;
    }
    catch (ex) {}
   }
  
   test(tries);
  }
  
  function test3() {
   function test(j) {
    var s = 0;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    for (var i = 0; i < j; i++) s = i;
    return s;
   }
  
   try {
    test(tries);
   }
   catch (ex) {}
  }
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

test1();

test2();

test3();

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

• Revision 1: published by Marco Rogers on 24th February 2011
• Revision 6: published on 23rd April 2013
• Revision 7: published 2 weeks ago
• Revision 9: published 1 week ago

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