Simple solution : ES6 Features "includes" method
let arr = [1, 2, 3, 2, 3, 2, 3, 4];
arr.includes(2) // true
arr.includes(93) // false
Simple solution : ES6 Features "includes" method
let arr = [1, 2, 3, 2, 3, 2, 3, 4];
arr.includes(2) // true
arr.includes(93) // false