Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.36
Chrome 100
Windows
Desktop
2 years ago
Test name Executions per second
Using indexOf 82.9 Ops/sec
Using lastIndexOf 346.4 Ops/sec
Using a Set 768.1 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.reduce((unique, item) => unique.includes(item) ? unique : [...unique, item], []);
  • Using a Set

     
    [...new Set(array)]