Run results for: Map vs WeakMap (real-world) Performance

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: 6 months ago

Test name	Executions per second
Conspicuous Map lookup	44.2 Ops/sec
Conspicuous WeakMap lookup	46.0 Ops/sec
Conspicuous Map lookup 2	44.6 Ops/sec
Conspicuous WeakMap lookup 2	46.4 Ops/sec

Script Preparation code:

var keyCount = 16384
var keys = []
var map = new Map()
var weakmap = new WeakMap()


// 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 = {}
  keys.push(key)
  map.set(key,val)
  weakmap.set(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 WeakMap lookup
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = weakmap.get(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 WeakMap lookup 2
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = weakmap.get(key) }

Run results for: Map vs WeakMap (real-world) Performance

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

Conspicuous Map lookup

Conspicuous WeakMap lookup

Conspicuous Map lookup 2

Conspicuous WeakMap lookup 2