Run results for: weakmap vs closure vs private symbols vs private symbol object

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Browser: Chrome 121

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

closure get

24.1M/s

closure incr

23.7M/s

symbol incr

23.5M/s

pso get

12.0M/s

pso incr

12.0M/s

weakmap get

11.7M/s

weakmap incr

7.7M/s

View exact numbers

Test name	Executions per second
✓ closure get	24,103,636 Ops/sec
closure incr	23,721,064 Ops/sec
symbol incr	23,504,584 Ops/sec
pso get	12,031,869 Ops/sec
pso incr	11,982,350 Ops/sec
weakmap get	11,672,696 Ops/sec
weakmap incr	7,659,549 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()

var so = {};
function D() {
    var sym = Symbol('x')
    so[sym] = 0
	var x = {
		incr() { so[sym]++ },
		get() { return so[sym] },
	}
	return x
}
var pso = D();
pso.incr()

Tests:

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