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/91.0.4472.106 YaBrowser/21.6.0.1108 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 21

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Using indexOf	90.7 Ops/sec
Using lastIndexOf	74.2 Ops/sec
Using a Set	656.2 Ops/sec

Script Preparation code:

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

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

Run results for: Methods to remove duplicates from array

Using indexOf

Using lastIndexOf

Using a Set