jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.

jsperf.com URLs are mirrored at the same path, e.g:

https://jsperf.com/negative-modulo/2

Can be accessed at:

https://jsperf.app/negative-modulo/2

in operator (v2)

Revision 2 of this benchmark created by WebReflection on August 9, 2011

Description

Same stuff done in version 1 except no function calls are involved.

http://jsperf.com/in-operator

Preparation HTML

<script>
  var
      // simple shim that *should* fail in old browsers
      // if getters/setters are not supported
      defineProperty = Object.defineProperty || function (o, k, v) {
          o.__defineGetter__(k, v.get);
          o.__defineSetter__(k, v.set);
          return o;
      },
      descriptor = {
          get: function () {
              return this._prop || {}; // let's say the default
          },
          set: function (_prop) {
              // here something more meaningful ...
              this._prop = _prop;
          }
      },
      descriptorSet = {
          get: function () {
              return this._prop;
          },
          set: function (_prop) {
              // here something more meaningful ...
              this._prop = _prop;
          }
      },
      object = {},
      globalResult
  ;
</script>

Test runner

Ready to run.

Testing in
Test		Ops/sec
in operator set	`globalResult = "prop" in object \|\| (object.prop = {}); object = {};`	ready
in operator	`// first one missing ... does not matter globalResult = "prop" in object \|\| (object.prop = {}); object = {prop:{}};`	ready
in operator + magic set	`globalResult = "prop" in object \|\| (object.prop = {}); object = defineProperty({}, "prop", descriptorSet);`	ready
in operator + magic	`globalResult = "prop" in object \|\| (object.prop = {}); object = defineProperty({}, "prop", descriptor);`	ready
common pattern set	`globalResult = (object.prop = object.prop \|\| {}); object = {};`	ready
common pattern	`// first one missing ... does not matter globalResult = (object.prop = object.prop \|\| {}); object = {prop:{}};`	ready
common pattern + magic set	`globalResult = (object.prop = object.prop \|\| {}); object = defineProperty({}, "prop", descriptorSet);`	ready
common pattern + magic	`globalResult = (object.prop = object.prop \|\| {}); object = defineProperty({}, "prop", descriptor);`	ready
better pattern set	`globalResult = object.prop \|\| (object.prop = {}); object = {};`	ready
better pattern	`// first one missing ... does not matter globalResult = object.prop \|\| (object.prop = {}); object = {prop:{}};`	ready
better pattern + magic set	`globalResult = object.prop \|\| (object.prop = {}); object = defineProperty({}, "prop", descriptorSet);`	ready
better pattern + magic	`globalResult = object.prop \|\| (object.prop = {}); object = defineProperty({}, "prop", descriptor);`	ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

Revision 1: published by WebReflection on August 9, 2011
Revision 2: published by WebReflection on August 9, 2011