Run details:
Mozilla/5.0 (X11; Linux x86_64; rv:122.0) Gecko/20100101 Firefox/122.0
Firefox 122
Linux
Desktop
11 months ago
Test name Executions per second
Using indexOf 340.2 Ops/sec
Using lastIndexOf 312.9 Ops/sec
Using a Set 667.6 Ops/sec
Script Preparation code:
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);
  • Using lastIndexOf

     
    array.filter((item, index) => array.lastIndexOf(item) != index);
  • Using a Set

     
    [...new Set(array)]