for vs forEach v2 (v341)

Revision 341 of this benchmark created on

Description

Is it faster to use the native forEach or just loop with for?

Preparation HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>
  var i, values = [],
      sum = 0;
  for (i = 0; i < 10000; i++) {
   values[i] = i;
  }
  
  function add(val) {
   sum += val;
  }
</script>

Setup

function iterate(array, delegate) {
      var length = array.length;
      for (var i = 0; i < length; i++) {
        delegate(array[i]);
      }
    }

Test runner

Ready to run.

Testing in
TestOps/sec
forEach
values.forEach(add);
ready
for loop, simple
for (i = 0; i < values.length; i++) {
  add(values[i]);
}
ready
for loop, cached length
var len = values.length;
for (i = 0; i < len; i++) {
  add(values[i]);
}
ready
for loop, reverse
for (i = values.length - 1; i >= 0; i--) {
  add(values[i]);
}
ready
for in
for (i in values) {
  add(values[i]);
}
ready
jQuery's each method
$.each(values, function(index) {
  add(values[index]);
});
ready
Custom iterator
//Custom iterator
Array.prototype.withAllDo = function(delegate) {
  var length = this.length;
  for (var i = 0; i < length; i++) {
    delegate(this[i]);
  }
};

values.withAllDo(add);
ready
Iteration method
iterate(values, add);
ready

Revisions

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