Run results for: Methods to remove duplicates from array

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/110.0.5481.114 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 110

Operating system: iOS 16.3

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
Using indexOf	261.8 Ops/sec
Using lastIndexOf	207.5 Ops/sec
Using a Set	1263.4 Ops/sec

Script Preparation code:

var array = [];
for (let i = 0; i < 100000; i++) {
   array.push(Math.floor((Math.random() * 10) + 1));
}

Tests:

Using indexOf
array.filter((item, index) => array.indexOf(item) != index);
Using lastIndexOf
array.filter((item, index) => array.lastIndexOf(item) != index);
Using a Set
[...new Set(array)]

Run results for: Methods to remove duplicates from array

Using indexOf

Using lastIndexOf

Using a Set