Run results for: Methods to remove duplicates from array

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/125.0.6422.80 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 125

Operating system: iOS 17.5

Device Platform: Mobile

Date tested: 2 years ago

Using a Set

969/s

Using indexOf

181/s

Using lastIndexOf

174/s

View exact numbers

Test name	Executions per second
✓ Using a Set	969 Ops/sec
Using indexOf	181 Ops/sec
Using lastIndexOf	174 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)]