Run results for: length or no length

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36

Browser: Chrome 70

Operating system: Mac OS X 10.14.0

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Loop Without Saving Length	6574.2 Ops/sec
Loop With Saving Length	6599.4 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