caching length

JavaScript performance comparison

Revision 3 of this test case created by Collection Performance

Preparation code

 
<script>
Benchmark.prototype.setup = function() {
    var arr=[];
    for(var i=0;i<1000;i++) {
      arr[i]=Math.random();
    }
};
</script>

Test runner

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

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
cached
for(var i=0,len=arr.length;i<len;i++) {
  arr[i]*=2;
}
pending…
not cached
for(var i=0;i<arr.length;i++) {
  arr[i]*=2;
}
pending…
u wot m8
var len=2;
len*=arr.length;
len-=len/2;
for(var i=0;i<len;i++) {
  arr[i]*=2;
}
pending…
while loop
var len = arr.length;
while (len--) {
  arr[len]*=2;
}
pending…
do-while loop
var len = arr.length;
do{
  arr[len]*=2;
} while (len--);
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. Here’s a list of current revisions for this page:

0 comments

Add a comment