Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36
Chrome 74
Windows
Desktop
5 years ago
Test name Executions per second
for 3.7 Ops/sec
forEach 75.9 Ops/sec
for...in 4.6 Ops/sec
Script Preparation code:
AخA
 
arr = [];
arr.length = 800000;
arr.fill(0)
Tests:
  • for

     
    let sum = 0;
    for (let i = 0; i < arr.length; i++) {
      sum += arr[i];
    }
  • forEach

     
    let sum = 0;
    arr.forEach(value => sum += value);
  • for...in

     
    let sum = 0;
    for (let i in arr) {
      sum += i;
    }