Run results for: Array foreach vs for..in

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser: Chrome 130

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
for in	85822.1 Ops/sec
foreach	392113.2 Ops/sec

Script Preparation code:

var array = [];
for(let i = 0; i <= 100; i++) {
  array[i] = i;
}

Tests:

for in
let sum = 0; for (var sample in array) { sum += Number(sample); } console.log(sum);
foreach
let sum = 0; array.forEach((sample) => { sum += sample; }); console.log(sum);