How to remove repetitive items from an array

repetitive_remover.js

var x = new Array(1000000).fill(0).map(item => Math.floor(Math.random()*10));

console.time('1.Set');
var setResult = Array.from(new Set(x));
console.timeLog('1.Set');
console.log(setResult);

console.time('2.Reduce');
var reduceResult = x.reduce((acc, item) => {
  if (acc.indexOf(item) === -1) {
    acc.push(item);
  }

  return acc;
}, []);
console.timeLog('2.Reduce');
console.log(reduceResult);

console.time('3.Filter');
var filterResult = x.filter((item, index) => x.indexOf(item) === index);
console.timeLog('3.Filter');
console.log(filterResult);

console.time('4.reducedObject');
var reducedObject = x.reduce((acc, item) => {
  acc[item] = item;

  return acc;
}, {});
var reducedObjectResult = Object.values(reducedObject);
console.timeLog('4.reducedObject');
console.log(reducedObjectResult);

I have the idea for the three first approaches from Ali Rajabi's post here. But the last approach was my own idea.