Run results for: Map vs Object (real-world) Performance (better) 2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser: Chrome 124

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

add arr

260/s

add map

224/s

Conspicuous Obj lookup 2

70/s

Conspicuous Obj lookup

66/s

Conspicuous Map lookup 2

66/s

Conspicuous Map lookup

64/s

View exact numbers

Test name	Executions per second
✓ add arr	260 Ops/sec
add map	224 Ops/sec
Conspicuous Obj lookup 2	70 Ops/sec
Conspicuous Obj lookup	66 Ops/sec
Conspicuous Map lookup 2	66 Ops/sec
Conspicuous Map lookup	64 Ops/sec

Script Preparation code:

var keyCount = 16384
var keys = []
var map = new Map()
var arr = []
var obj = Object.create(null)
delete obj.x


// Hide lookup keys to prevent V8 cheating (AKA Optimizing)
var getConspicuousKey = seed => keys[Math.floor(seed * keyCount)]


// Setup out test objects w/ random values
for (let i=0; i<keyCount; i++) {
  let val = Math.random()
  let key = Math.random().toString()
  keys.push(key)
  map.set(key,val)
  obj[key] = val
}

Tests:

Conspicuous Map lookup
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = map.get(key) }
Conspicuous Obj lookup
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = obj[key] }
Conspicuous Map lookup 2
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = map.get(key) }
Conspicuous Obj lookup 2
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = obj[key] }
add arr
const arr1 = [] for (let i=0; i<keyCount; i++) { let v = Math.random() arr1.push(v) }
add map
const map1 = new Map() for (let i=0; i<keyCount; i++) { let v = Math.random() map1.set(i,v) }