Run results for: length or no length

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0

Browser: Firefox 91

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Loop Without Saving Length	6386.3 Ops/sec
Loop With Saving Length	6517.2 Ops/sec

Script Preparation code:

var data = Array.from(Array(10).keys());

function loopWithLength(arr) {
  var length = arr.length;
  for (var i = 0; i < length; i++) {
    console.log(arr[i]);
  }
}

function loopWithoutLength(arr) {
  for (var i = 0; i < arr.length; i++) {
    console.log(arr[i]);
  }
}

Tests:

Loop Without Saving Length
loopWithoutLength(data)
Loop With Saving Length
loopWithLength(data)

Run results for: length or no length

Loop Without Saving Length

Loop With Saving Length