if value not in list js code example

Example 1: check value exist in array javascript

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(1, 2);  // false (second parameter is the index position in this array at which to begin searching)

Example 2: js array contains

let fruits = ["Banana", "Orange", "Apple", "Mango"];
let do_contain = fruits.includes("Mango"); // contain: true