Converting arguments to an array

JavaScript performance comparison

Revision 2 of this test case created

Preparation code

<script>
  function push() {
      var x = [];
      x.push.apply(x, arguments);
      return x;
  }
  function unshift() {
      var x = [];
      x.unshift.apply(x, arguments);
      return x;
  }
  function _callPush(args) {
     var x = [];
     x.push.apply(x, args);
     return x;
  }
  function callPush() {
      return _callPush(arguments);
  }
  function _callUnshift(args) {
      var x = [];
      x.unshift.apply(x, args);
      return x;
  }
  function callUnshift(args) {
      return _callUnshift(arguments);
  }
 
  var bigArray = ((new Array(1000)).join("a,") + "a").split(",");
 
  unshift.apply(null, bigArray).length === bigArray.length || alert('unshift broken');
  push.apply(null, bigArray).length === bigArray.length || alert('push broken');
  callPush.apply(null, bigArray).length === bigArray.length || alert('callPush broken');
  callUnshift.apply(null, bigArray).length === bigArray.length || alert('callUnshift broken');
 
</script>

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Testing in unknown unknown
Test Ops/sec
Push
push.apply(null, bigArray);
pending…
Push w/fn call
callPush.apply(null, bigArray);
pending…
Unshift
unshift.apply(null, bigArray);
pending…
Unshift w/fn call
callUnshift.apply(null, bigArray);
pending…

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