Object keys iteration

JavaScript performance comparison

Revision 36 of this test case created

Info

Testing Object.keys vs for-in. I've added jQuery's .each() for my own testing.

Preparation code

<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>
  var data = {};
 
  for (var i = 0; i < 5000; i++) {
 
   data[i] =  'user ' + i;
 
  }

  for (var j = i; j < 7500; j++) {
 
   data[j] = undefined;
 
  }
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
for-in
for (var key in data) {
  data[key];
}
pending…
object-keys
Object.keys(data).forEach(function(element, index, array) {
  data[element];
});
pending…
object-keys 2
var keys = Object.keys(data);
var len = keys.length;
var i = 0;

while (i < len) {
  data[keys[i]];
  i++;
}
pending…
object-keys 3
var keys = Object.keys(data);
var len = keys.length;
var i;
var prop;

for (i = 0; i < len; i++) {
  data[keys[i]];
}
pending…
$: [..].each() addressing using key
var keys = Object.keys(data);
$.each(keys ,function(i) {
    data[keys[i]];
});
pending…

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Revisions

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