Run results for: weakmap vs closure vs private symbols

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser: Chrome 129

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

symbol incr

22.8M/s

closure get

21.1M/s

closure incr

20.8M/s

weakmap get

10.3M/s

weakmap incr

6.5M/s

View exact numbers

Test name	Executions per second
✓ symbol incr	22,759,024 Ops/sec
closure get	21,073,060 Ops/sec
closure incr	20,810,210 Ops/sec
weakmap get	10,293,698 Ops/sec
weakmap incr	6,524,745 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()