Run results for: while, for, for-of, map

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser: Chrome 123

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

for-of

18/s

.map

12/s

for

6/s

while

6/s

View exact numbers

Script Preparation code:

var arr = Array(1_000_000);
for (let i = 0; i < 1_000_000; i++) {
  arr[i] = { num: Math.random() };
}

Tests:

while
var newArr = []; let l = arr.length; let i = -1; while (++i < l) { newArr.push(arr[i].num); }
for
var newArr = []; var l = arr.length; for (var i = 0; i < l; i++) { newArr.push(arr[i].num); }
for-of
var newArr = []; for (var val of arr) { newArr.push(val.num); }
.map
var newArr = arr.map(val => val.num);