Run results for: Array.includes vs Set.has vas Map.has vs object[k] !== undefined (length 1 million)

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36

Browser: Chrome 143

Operating system: Linux

Device Platform: Desktop

Date tested: 7 months ago

map.has(key)

179.5M/s

set.has(key)

167.4M/s

obj[key] !== undefined

152.5M/s

arr.includes(key)

31K/s

View exact numbers

Test name	Executions per second
✓ map.has(key)	179,498,096 Ops/sec
set.has(key)	167,375,344 Ops/sec
obj[key] !== undefined	152,510,512 Ops/sec
arr.includes(key)	31,444 Ops/sec

Script Preparation code:

const array = Array.from({ length: 1_000_000 }, (v, k) => k);
const entries = array.map((n) => [n,n]);

var arr = [...array];
var set = new Set(array);
var map = new Map(entries);
var obj = Object.fromEntries(entries);
var key = 770908;

Tests:

arr.includes(key)
return arr.includes(key);
set.has(key)
return set.has(key);
map.has(key)
return map.has(key);
obj[key] !== undefined
return obj[key] !== undefined