Run results for: weakmap vs closure vs private symbols

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser: Chrome 122

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

closure get

28.2M/s

symbol incr

28.0M/s

closure incr

27.6M/s

weakmap get

13.1M/s

weakmap incr

8.4M/s

View exact numbers

Test name	Executions per second
✓ closure get	28,150,444 Ops/sec
symbol incr	28,029,070 Ops/sec
closure incr	27,556,226 Ops/sec
weakmap get	13,089,012 Ops/sec
weakmap incr	8,385,952 Ops/sec

Script Preparation code:

function A() {
	var x = 0;
	return {
		incr() { x ++ },
		get() { return x },
	}
}
var closure = A();
closure.incr()

var wm = new WeakMap();
function B() {
	var x = {
		incr() { wm.set(x, (wm.get(x) || 0) + 1) },
		get() { return wm.get(x) },
	}
	return x
}
var weakmap = B();
weakmap.incr()


function C() {
	var me = Symbol('me');
	var x = {
		incr() { x[me]++ },
		get() { return x[me] },
		[me]: 0,
	}
	return x
}
var symbols = C();
symbols.incr()

Tests:

closure get
closure.get()
weakmap get
weakmap.get()
closure incr
closure.incr()
weakmap incr
weakmap.incr()
symbol incr
symbols.incr()