Run results for: findIndex vs indexOf - JavaScript performance

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_3_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.3.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.3.1

Device Platform: Mobile

Date tested: 2 years ago

indexOf

520K/s

findIndex

6K/s

View exact numbers

Test name	Executions per second
✓ indexOf	520,132 Ops/sec
findIndex	6,167 Ops/sec

Script Preparation code:

var arr = new Array(15000);
arr.fill({ id: 0 });
arr = arr.map((el, idx) => el.id = idx);
var foo = Math.floor(Math.random() * 15000);

Tests:

findIndex
var index = arr.findIndex((num) => num === foo);
indexOf
var index = arr.indexOf(foo);