Run results for: Object look-up

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0

Browser: Firefox 57

Operating system: Windows 7

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
access property with prototype	1360200.0 Ops/sec
access property without prototype	1359543.0 Ops/sec
in with prototype	1444515.0 Ops/sec
in without prototype	1385173.0 Ops/sec
hasOwnProperty with prototype	1033283.0 Ops/sec
hasOwnProperty without prototype	1016809.0 Ops/sec

Script Preparation code:

var withPrototype = {};
var withoutPrototype = Object.create(null);

for (var i=0; i<100; ++i) {
  withPrototype[i] = true;
  withoutPrototype[i] = true;
}

var hasOwnProperty = Object.prototype.hasOwnProperty;

Tests:

access property with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (withPrototype[key]) continue; }
access property without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (withoutPrototype[key]) continue; }
in with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (key in withPrototype) continue; }
in without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (key in withoutPrototype) continue; }
hasOwnProperty with prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (hasOwnProperty.call(withPrototype, key)) continue; }
hasOwnProperty without prototype
for (var i=0; i<100; ++i) { var key = ''+i; if (hasOwnProperty.call(withoutPrototype, key)) continue; }

Run results for: Object look-up

access property with prototype

access property without prototype

in with prototype

in without prototype

hasOwnProperty with prototype

hasOwnProperty without prototype