Run results for: Map vs Object (real-world) Performance (disabling object-specific optimizations and default keys)

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36

Browser: Chrome 111

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Conspicuous Map lookup	63.7 Ops/sec
Conspicuous Obj lookup	56.8 Ops/sec
Conspicuous Map lookup 2	65.0 Ops/sec
Conspicuous Obj lookup 2	56.7 Ops/sec

Script Preparation code:

var keyCount = 16384
var keys = []
var map = new Map()
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()
  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] }

Run results for: Map vs Object (real-world) Performance (disabling object-specific optimizations and default keys)

Lookup of map vs object (in a real-world test format)

Conspicuous Map lookup

Conspicuous Obj lookup

Conspicuous Map lookup 2

Conspicuous Obj lookup 2