Run results for: Methods to remove duplicates from array

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36 OPR/113.0.0.0 (Edition GX-CN)

Browser: Opera 113

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Using a Set

982/s

Using indexOf

229/s

Using lastIndexOf

194/s

View exact numbers

Test name	Executions per second
✓ Using a Set	982 Ops/sec
Using indexOf	229 Ops/sec
Using lastIndexOf	194 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)]