string concat vs array join

JavaScript performance comparison

Revision 9 of this test case created by and last updated

Preparation code


      
      <script>
Benchmark.prototype.setup = function() {
  var words = ['this', 'is', 'a', 'test'];
  
  var counter = 0;
  var length = 10000;
  var i;
  
  var re = /z/;
  var result;

};
</script>

Test runner

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

Java applet disabled.

Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
Concat
var text = words[0];
for(i = 1; i < length; ++i)
{
    text += ' ' + words[i & 3] + (counter++);
}

result = re.test(text);
pending…
Join
var a = [words[0]];
for(i = 1; i < length; ++i)
{
    a.push(' ', words[i & 3], counter++);
}

result = re.test(a.join(''));
pending…
Join without push()
var a = [words[0]];
for(i = 1; i < length; ++i)
{
    a[i] = ' ' + words[i & 3] + (counter++);
}

result = re.test(a.join(''));
pending…

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.

0 Comments