Run results for: Iterator vs Index for loop (cached array length fixed)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36 Edg/133.0.0.0

Browser: Chrome 133

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Index for loop

22K/s

Iterator for loop

19K/s

View exact numbers

Test name	Executions per second
✓ Index for loop	22,204 Ops/sec
Iterator for loop	19,374 Ops/sec

Script Preparation code:

var arr = [];
for(let i = 0; i < 10000; i++) {
  arr.push(Math.random());
}
var arrLength = arr.length;

Tests:

Iterator for loop
let sum = 0; for(const num of arr) { sum += num; }
Index for loop
let sum = 0; for(let i = 0; i < arrLength; i++) { sum += arr[i]; }