Array.prototype.includes()

const array = [1, 2, 3];

console.log(array.includes(2));
// : true

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

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

console.log(pets.includes("at"));
// : false

includes(searchElement)
includes(searchElement, fromIndex)

[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
["1", "2", "3"].includes(3); // false

const arr = ["a", "b", "c"];

arr.includes("c", 3); // false
arr.includes("c", 100); // false

//  3
// fromIndex  -100
//  3 + (-100) = -97

const arr = ["a", "b", "c"];

arr.includes("a", -100); // true
arr.includes("b", -100); // true
arr.includes("c", -100); // true
arr.includes("a", -2); // false

console.log([1, , 3].includes(undefined)); // true

const arrayLike = {
  length: 3,
  0: 2,
  1: 3,
  2: 4,
  3: 1, // length  3  includes() 
};
console.log(Array.prototype.includes.call(arrayLike, 2));
// true
console.log(Array.prototype.includes.call(arrayLike, 1));
// false