Run results for: map vs reverse for vs for vs push vs unshift

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.5.1

Device Platform: Mobile

Date tested: one year ago

map

34K/s

reverse for

22K/s

for

16K/s

for push

16K/s

reverse for unshift

14K/s

View exact numbers

Script Preparation code:

var arr = new Array(500).fill().map(()=>({id:Math.random()**Math.random()**Math.random()}));

Tests:

map
const res1=arr.map(({id})=>id>Math.random()?{foo:'bar'}:{bar:'foo'});
reverse for
const res2=new Array(arr.length); for (let i=arr.length-1;i>-1;i--){ res2[i]=arr[i].id>Math.random()?{foo:'bar'}:{bar:'foo'} }
for
const res2=new Array(arr.length); for (let i=0;i<arr.length;i++){ res2[i]=arr[i].id>Math.random()?{foo:'bar'}:{bar:'foo'} }
for push
const res2=[] for (let i=0;i<arr.length;i++){ res2.push(arr[i].id>Math.random()?{foo:'bar'}:{bar:'foo'}) }
reverse for unshift
const res2=new Array(); for (let i=arr.length-1;i>-1;i--){ res2.unshift(arr[i].id>Math.random()?{foo:'bar'}:{bar:'foo'}) }