for vs forEach

JavaScript performance comparison

Revision 160 of this test case created by

Preparation code

<script>
  Benchmark.prototype.setup = function() {
    var array = [];
    
    for( var i = 0; i < 1000; i++) {
        array.push(i);
    }
    
    function logIt(val){
        console.log(val);
    }
  };


Array.prototype.forEach2 = function (a, scope) {
            var l = this.length, i = 0;
            if(scope){
                for (; i < l; i++) {
                    a.call(scope, this[i], i);
                }
            }else{
                for (; i < l; i++) {
                    a(this[i], i);
                }
            }
        };
Array.prototype.forEach3 = function (a, scope) {
            var l = this.length, i = 0;
for (; i < l; i++) {
                    scope?a.call(scope, this[i], i):a(this[i], i);
                }
           
        };
</script>
    

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
for loop
for (i = 0, ii = array.length; i < ii; i++) {
  logIt(array[i]);
}
pending…
forEach
array.forEach(logIt);
pending…
for loop, reverse
for (i = array.length - 1; i >= 0; i--) {
  logIt(array[i]);
}
pending…
for key in object
for (key in array) {
  logIt(array[key]);
}
pending…
forEach with anonymous function
array.forEach(function(val) {
  console.log(val)
});
pending…
foreach2
array.forEach2(logIt);
pending…
foreach3
array.forEach3(logIt);
pending…

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Revisions

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