Run results for: Array.from() versus checking to see if item is already an array

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.2 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 7 months ago

No check to see if there is an array

77K/s

Check to see if there is an array

70K/s

View exact numbers

Test name	Executions per second
✓ No check to see if there is an array	76,678 Ops/sec
Check to see if there is an array	69,924 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Tests:

No check to see if there is an array
const [Builder, add] = (Math.random() > 0.5) ? [Array, 'push'] : [Set, 'add']; const collection = new Builder(); for (let i = 0; i < 1000; i++) { collection[add](i); } const result = Array.from(collection);
Check to see if there is an array
const [Builder, add] = (Math.random() > 0.5) ? [Array, 'push'] : [Set, 'add']; const collection = new Builder(); for (let i = 0; i < 1000; i++) { collection[add](i); } const result = Array.isArray(collection) ? collection : Array.from(collection);