Remove duplicate item from an array js code example

Example 1: js delete duplicates from array

const names = ['John', 'Paul', 'George', 'Ringo', 'John'];

let unique = [...new Set(names)];
console.log(unique); // 'John', 'Paul', 'George', 'Ringo'

Example 2: how to remove duplicates in array in javascript

const numbers = [1 , 21, 21, 34 ,12 ,34 ,12];
const removeRepeatNumbers = array => [... new Set(array)]
removeRepeatNumbers(numbers) // [ 1, 21, 34, 12 ]

Example 3: remove duplicate array es6

let a = [10,20,30,50,30];
let b = a.reduce((unique,item) => unique.includes(item) ? unique: [... unique, item] ,[]); 
console.log(b);