js lists prevent duplicates code example
Example 1: javascript remove duplicates from array
var myArr = [1, 2, 2, 2, 3];
var mySet = new Set(myArr);
myArr = [...mySet];
console.log(myArr);
// 1, 2, 3
Example 2: js delete duplicates from array
const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
let x = (names) => names.filter((v,i) => names.indexOf(v) === i)
x(names); // 'John', 'Paul', 'George', 'Ringo'