Object.keys vs for in for values

JavaScript performance comparison

Revision 20 of this test case created by Tomasz

Preparation code

<script>

</script>
<script>
Benchmark.prototype.setup = function() {
    var keys = Object.keys;
    var hasOwnProperty = Object.prototype.hasOwnProperty;
    var getProps = Object.getOwnPropertyNames;
   
    var obj = {
      'prop1': 'value1',
      'prop2': 'value2',
      'prop3': 'value3',
      'prop4': 'value4',
      'prop5': 'value5',
      'prop6': 'value6',
      'prop7': 'value7',
      'prop8': 'value8',
      'prop9': 'value9',
      'prop10': 'value10'
    };
    if (typeof Object.setPrototypeOf === 'function') {
      Object.setPrototypeof(obj, null);
    } else {
      obj.__proto__ = null;
    }
};
</script>

Test runner

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Testing in unknown unknown
Test Ops/sec
Object.keys
var props = keys(obj),
  index = -1,
  length = props.length,
  values = [];

while (++index < length) {
  values.push(obj[props[index]]);
}
pending…
Object.keys w/ forEach()
var values = [];
keys(obj).forEach(function(v,k,a) {
  values.push(obj[v]);
});
pending…
for-in w/ hasOwnProperty
var values = [];
for (var prop in obj) {
  hasOwnProperty.call(obj,prop)&&values.push(obj[prop]);
}
pending…
Object.getOwnProperties
var props = getProps(obj),
    i = props.length,
    values = [];

while(--i >= 0) {
    values.push(obj[props[i]]);
}
pending…
`Object.keys´ /w for...loop
var props = keys(obj),
  values = [];

for (var i=0, l=props.length; i<l; i++) {
  values.push(obj[props[i]]);
}
pending…

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