Run results for: empty an array in JavaScript - [] vs setting length

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser: Chrome 134

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

New empty array

47K/s

Set length to zero

47K/s

View exact numbers

Test name	Executions per second
✓ New empty array	47,083 Ops/sec
Set length to zero	46,924 Ops/sec

Tests:

Set length to zero
var size = 10000; var arr2 = []; for (var i = 0; i < size; i++){ arr2.push(i); } arr2.length = 0;
New empty array
var size = 10000; var arr3 = []; for (var i = 0; i < size; i++){ arr3.push(i); } arr3 = [];