Run results for: WeakMap vs Symbol 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36 Edg/129.0.0.0

Browser: Chrome 129

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

WeakMap set

12.1M/s

Symbol Property set

11.0M/s

Symbol Property get

5.0M/s

WeakMap get

5.0M/s

Symbol Property get (from own descriptor)

3.2M/s

Symbol Property get (if hasOwn)

2.9M/s

View exact numbers

Test name	Executions per second
✓ WeakMap set	12,068,345 Ops/sec
Symbol Property set	10,981,743 Ops/sec
Symbol Property get	4,992,260 Ops/sec
WeakMap get	4,988,339 Ops/sec
Symbol Property get (from own descriptor)	3,243,163 Ops/sec
Symbol Property get (if hasOwn)	2,923,386 Ops/sec

Script Preparation code:

var to0 = {};
var to1 = {};
var wm = new WeakMap();
var sy = Symbol();
wm.set(to1, 1);
to1[sy] = 1;
window.r = 0

Tests:

WeakMap set
wm.set(to0, 1);
Symbol Property set
to0[sy] = 1;
WeakMap get
r = wm.get(to1);
Symbol Property get
r = to1[sy];
Symbol Property get (from own descriptor)
r = Object.getOwnPropertyDescriptor(to1, sy).value;
Symbol Property get (if hasOwn)
r = Object.hasOwn(sy) ? to1[sy] : undefined;