const names = ['John', 'Paul', 'George', 'Ringo', 'John']; let unique = [...new Set(names)]; console.log(unique); // 'John', 'Paul', 'George', 'Ringo'
var data = [1, 2, 'Peter', 3, 3,'Peter', 2, 2, 1, 2, 3, 4, 4, 5, 4]; var unique = data.filter((v, i, a) => a.indexOf(v) === i);
const names = ['John', 'Paul', 'George', 'Ringo', 'John']; let x = (names) => names.filter((v,i) => names.indexOf(v) === i) x(names); // 'John', 'Paul', 'George', 'Ringo'
let a = [10,20,30,10,30]; let b = a.filter((item,index) => a.indexOf(item) === index); console.log(b);
function getNotUnique(array) { var map = new Map(); array.forEach(a => map.set(a, (map.get(a) || 0) + 1)); return array.filter(a => map.get(a) > 1); } console.log(getNotUnique([1, 2, 2, 4, 4])); //[2, 2, 4, 4] console.log(getNotUnique([1, 2, 3] )); //[]
let a = [10,20,30,10,30]; let b = [... new Set(a)]; console.log(b);
let a = [10,20,30,50,30]; let b = a.reduce((unique,item) => unique.includes(item) ? unique: [... unique, item] ,[]); console.log(b);