Preparation code

<script type="text/javascript">
  var definedProperty = function () {
    Object.defineProperty(this, "prop", {
      configurable: true, enumerable: true, value: 1
    });
  }

  var definedConstantProperty = function () {
    Object.defineProperty(this, "prop", {
      configurable: true, 
      enumerable: true, 
      value: 1, 
      writable: false
    });
  }

  var definedValueOnlyProperty = function () {
    Object.defineProperty(this, "prop", {
      value: 1, 
    });
  }

  var regularProperty = function () {
    this.prop = 1;
  }
  
  var count = 50000;
  var defineds = new Array(count);
  var definedConsts = new Array(count);
  var definedValues = new Array(count);
  var regulars = new Array(count);

  for (var i = 0; i < count; i++) {
    defineds[i] = new definedProperty();
    definedConsts[i] = new definedConstantProperty();
    definedValues[i] = new definedValueOnlyProperty();
    regulars[i] = new regularProperty();
  }
</script>

Test runner

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var sum = 0;
for (var i = 0, a = defineds; i < count; i++) {
  sum += a[i].prop;
}

var sum = 0;
for (var i = 0, a = regulars; i < count; i++) {
  sum += a[i].prop;
}

var sum = 0;
for (var i = 0, a = definedConsts; i < count; i++) {
  sum += a[i].prop;
}

var sum = 0;
for (var i = 0, a = definedValues; i < count; i++) {
  sum += a[i].prop;
}

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Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

• Revision 1: published by Kevin Gadd on 10th July 2012
• Revision 3: published on 9th January 2013
• Revision 4: published on 2nd March 2013

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