for vs forEach

JavaScript performance comparison

Revision 565 of this test case created by Poul Kruijt

Preparation code

<script>
  var i, values = [],
      sum = 0;
  for (i = 0; i < 10000; i++) {
   values[i] = i;
  }
  
  function add(val) {
   sum += val;
  }
</script>
    

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
for loop, reverse
for (i = values.length - 1; i >= 0; i--) {
 add(values[i]);
}

console.log(sum);
pending…
forEach arrow
values.forEach((val) => sum += val);

console.log(sum);
pending…
forEach more local
(function() {
 var sum = 0;
 values.forEach(function(val) {
  sum += val;
 });

 console.log(sum);
})();
pending…
for loop, cached length
var len = values.length;
for (i = 0; i < len; i++) {
 add(values[i]);
}

console.log(sum);
pending…
forEach less local
values.forEach(function(val) {
 sum += val;
});

console.log(sum);
pending…
for loop, simple
for (i = 0; i < values.length; i++) {
 add(values[i]);
}

console.log(sum);
pending…
forEach
values.forEach(add);

console.log(sum);
pending…

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Revisions

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