Run results for: isArray vs nullish coalesce + length check

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.3.1 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Array.isArray

601.2M/s

Check object.length

132.7M/s

View exact numbers

Test name	Executions per second
✓ Array.isArray	601,194,432 Ops/sec
Check object.length	132,709,568 Ops/sec

Script Preparation code:

function myIsArray(obj){
  return (obj ?? []).length > 0;
}

var isArray = Array.isArray

Tests: