Run results for: Array looping - for, Array.forEach, for-of, array.entries()

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

for-of - Access value only

1.1M/s

Array.forEach - Access index and value

283K/s

Array.forEach - Access value only

247K/s

for-of + Array.entries

97K/s

Simple for loop - Access value only

52K/s

Simple for loop - Access index and value

51K/s

View exact numbers

Test name	Executions per second
✓ for-of - Access value only	1,067,341 Ops/sec
Array.forEach - Access index and value	282,875 Ops/sec
Array.forEach - Access value only	246,597 Ops/sec
for-of + Array.entries	97,338 Ops/sec
Simple for loop - Access value only	51,568 Ops/sec
Simple for loop - Access index and value	51,405 Ops/sec

Script Preparation code:

var arr = [];

for( var cpt = 0; cpt < 1000; cpt++ ) {
  arr.push( Math.random() );
}

var someFn = function( item ) {
  return item * 3 + item / 5;
}

Tests:

Simple for loop - Access index and value
let total = 0; for( var i = 0, n = arr.length; i < n; i++ ) { total += i + arr[i]; }
Array.forEach - Access index and value
let total = 0; arr.forEach((value, i) => { total += i + value; });
for-of + Array.entries
let total = 0; for(const [i, value] of arr.entries()) { total += i + value; }
for-of - Access value only
let total = 0; for(const value of arr) { total += value; }
Simple for loop - Access value only
let total = 0; for( var i = 0, n = arr.length; i < n; i++ ) { total += arr[i]; }
Array.forEach - Access value only
let total = 0; arr.forEach((value) => { total += value; });