Элемент JavaScript в массиве
var letters = ["A", "B", "C", "D"];
var result = letters.includes("A");
// result will be TRUE or FALSE
Terrible Tern
var letters = ["A", "B", "C", "D"];
var result = letters.includes("A");
// result will be TRUE or FALSEvar fruits = ["Banana", "Orange", "Apple", "Mango"];
var n = fruits.includes("Mango");var a = [1, 2, 3];
a.includes(2); // true
a.includes(4); // false