javascript test if array contains a string code example

Example 1: javascript array contains

var fruits = ["Banana", "Orange", "Apple", "Mango"];
var n = fruits.includes("Mango");

Example 2: how to check if an array contains a number in javascript

// To check if an array contains a number
const ratings = [1,2,3,4,5];

let result = ratings.includes(4); 
console.log(result); // true

result = ratings.includes(6); 
console.log(result); // false

Example 3: check if array contain the all element javascript

const myArray: number[] = [2, 4, 6, 8, 10, 12, 14, 16];
const elements: number[] = [4, 8, 12, 16];

function containsAll(arr: number[]) {
  return (
    arr.includes(elements[0]) &&
    arr.includes(elements[1]) &&
    arr.includes(elements[2]) &&
    arr.includes(elements[3])
  );
}
console.log(containsAll(myArray));

or you could use the following line:

function c2(arr: number[]) {
  return elements.every((val: number) => arr.includes(val));
}