array js includes code example

Example 1: javascript array contains

var colors = ["red", "blue", "green"];
var hasRed = colors.includes("red"); //true
var hasYellow = colors.includes("yellow"); //false

Example 2: js array includes

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(3, 3);  // false
[1, 2, 3].includes(3, -1); // true
[1, 2, NaN].includes(NaN); // true

Example 3: javascript includes

const pets = ['cat', 'dog', 'bat'];

console.log(pets.includes('cat'));
// output: true

Example 4: array includes

let storyWords = ['extremely', 'literally', 'actually', 'hi', 'bye', 'okay']
let unnecessaryWords = ['extremely', 'literally', 'actually' ];

let betterWords = storyWords.filter(function(word) {
  return !unnecessaryWords.includes(word);
});
console.log(betterWords) // ['hi' 'bye' 'okay]

Example 5: 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));
}