Run results for: custom function vs conversion to array+ at()

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:103.0) Gecko/20100101 Firefox/103.0

Browser: Firefox 103

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
function	733495.1 Ops/sec
convert to array	715720.6 Ops/sec

Tests:

function
function getLastValue(set){ let value; for(value of set); return value; } const map1 = new Map(); map1.set('a', []); map1.set('b', [{a:2}]); map1.set('c', [1,2,3,4]); getLastValue(map1); map1.delete('c'); getLastValue(map1);
convert to array
const map1 = new Map(); map1.set('a', []); map1.set('b', [{a:2}]); map1.set('c', [1,2,3,4]); [...map1].at(-1) || [] map1.delete('c'); [...map1].at(-1) || []