Run results for: edit map vs slice no index start

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 13_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 13

Operating system: iOS 13.3.1

Device Platform: Mobile

Date tested: 4 years ago

Test name	Executions per second
map	114603.2 Ops/sec
slice	156458.7 Ops/sec

Script Preparation code:

window.arr = new Array(2000).fill({value: 'old'});
arr[0] = {value: 'toReplace'};

Tests:

map
const newArr = arr.map((item) => item.value === 'toReplace' ? {value: 'new'} : item);
slice
const editIndex = arr.findIndex(item => item.value === 'toReplace'); const newArr = [ ...arr.slice(0, editIndex), {value: 'new'}, ...arr.slice(editIndex + 1), ];

Run results for: edit map vs slice no index start

Which is faster?

map

slice