Run results for: Negation vs strict undefined

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.6 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Strict void 0

430.8M/s

Strict undefined

420.8M/s

Negation

207.4M/s

View exact numbers

Script Preparation code:

var map = new Map();
map.set('x', 1);
map.set('y', 2);

Tests:

Negation
const z = map.get('z'); if (!z) { map.set('z', 3); }
Strict undefined
const z = map.get('z'); if (z === undefined) { map.set('z', 3); }
Strict void 0
const z = map.get('z'); if (z === void 0) { map.set('z', 3); }