var arr = [2,2,33,4,1,5,33,4,4,7,8]
ES6
1,forEach
const unique1 = arr => { let obj = {} arr.forEach (value =>{ obj[value] = 0 }) console.log(obj) return Object.keys(obj) } console.log(unique1(arr)) // ["1", "2", "4", "5", "7", "8", "33"]
2,filter
const unique2 = arr => { return arr.filter( (el,index,array) => { return index === array.indexOf(el) }) } console.log(unique2(arr)) // [2, 33, 4, 1, 5, 7, 8]
3,set
const unique3 = arr => { return [...new Set(arr)] } console.log(unique3(arr)) // [2, 33, 4, 1, 5, 7, 8]