Run results for: Object.defineProperty vs Object.defineProperties

Run details:

User agent: Mozilla/5.0 (Android 14; Mobile; rv:123.0) Gecko/123.0 Firefox/123.0

Browser: Firefox Mobile 123

Operating system: Android

Device Platform: Mobile

Date tested: 6 months ago

Test name	Executions per second
Object.defineProperty	3053.8 Ops/sec
Object.defineProperties	2253.1 Ops/sec

Script Preparation code:

function Item() { 
	this._a = 0;
  	this._b = 0;
  	this._c = 0;
  	this._d = 0;
}

function create(ctor) {
	var res;
  	for (var i = 0; i < 100; i++) {
		var item = ctor();
      	if (res === void 0 || Math.random() < 0.5) {
         	res = item; 
        } 
    }
  	return res;
}

function update(item) {
 	item.a = item.b;
  	item.c = item.d;
}

Tests:

Object.defineProperty
function ctor() { var obj = new Item(); Object.defineProperty(obj, "a", { get: function() { return this._a; }, set: function(value) { this._a += value; } }); Object.defineProperty(obj, "b", { get: function() { return this._b * 2; }, set: function(value) { this._b += value + 2; } }); Object.defineProperty(obj, "c", { get: function() { return this._c * 4; }, set: function(value) { this._c += value / 2; } }); Object.defineProperty(obj, "d", { get: function() { return this._d * 3; }, set: function(value) { this._d += value - 1; } }); return obj; } window.leak = update(create(ctor));
Object.defineProperties
function ctor() { var obj = new Item(); Object.defineProperties(obj, { a: { get: function() { return this._a; }, set: function(value) { this._a += value; } }, b: { get: function() { return this._b * 2; }, set: function(value) { this._b += value + 2; } }, c: { get: function() { return this._c * 4; }, set: function(value) { this._c += value / 2; } }, d: { get: function() { return this._d * 3; }, set: function(value) { this._d += value - 1; } } }); return obj; } window.leak = update(create(ctor));