Run results for: iterate over map vs map entries vs map values vs array-backed map

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36

Browser: Chrome 141

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 9 months ago

array-backed map

178.9M/s

map values

137.5M/s

map entries

81.9M/s

map

79.4M/s

View exact numbers

Test name	Executions per second
✓ array-backed map	178,940,432 Ops/sec
map values	137,471,920 Ops/sec
map entries	81,931,488 Ops/sec
map	79,446,616 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

const map = new Map([[1,null],[2, null],[3, null],[4, null]])
const array = [1,2,3,4]
const mapWithArray = new Map([[1,null],[2, null],[3, null],[4, null]])
function getStructures() {
 return { map, array, mapWithArray } 
}

Tests:

map
const {map, array, mapWithArray} = getStructures() for (const [key, value] of map) { key; value; }
array-backed map
const {map, array, mapWithArray} = getStructures() for (const key of array) { key; mapWithArray.get(key) }
map entries
const {map, array, mapWithArray} = getStructures() const entries = map.entries() for (const [key, value] of entries) { key; value; }
map values
const {map, array, mapWithArray} = getStructures() const values = map.values() for (const key of values) { key; mapWithArray.get(key) }