Run results for: WeakMap vs Symbol Property

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/122.0.6261.62 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 122

Operating system: iOS 17.2

Device Platform: Mobile

Date tested: 2 years ago

WeakMap get

11.4M/s

Symbol Property set

11.0M/s

WeakMap set

10.7M/s

Symbol Property get

10.4M/s

View exact numbers

Test name	Executions per second
✓ WeakMap get	11,401,273 Ops/sec
Symbol Property set	11,028,344 Ops/sec
WeakMap set	10,690,721 Ops/sec
Symbol Property get	10,422,294 Ops/sec

Script Preparation code:

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

Tests:

WeakMap set
wm.set(to0, 1);
Symbol Property set
to0[sy] = 1;
WeakMap get
let r = wm.get(to1);
Symbol Property get
let r = to1[sy];