1myArray = Array(/*element1, element2, etc...*/);
2
3// If the array 'myArray' contains the element 'valueWeSearch'
4if(myArray.includes(valueWeSearch))
5{
6 	// Do something
7}

1var fruits = ["Banana", "Orange", "Apple", "Mango"];
2
3var n = fruits.includes("Mango"); // true
4
5var n = fruits.includes("Django"); // false

1 var fruits = ["Apple", "Banana", "Mango", "Orange", "Papaya"];
2    
3    // Check if a value exists in the fruits array
4    if(fruits.indexOf("Mango") !== -1){
5        alert("Value exists!")
6    } else{
7        alert("Value does not exists!")
8    }

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

1const fruits = ["Banana", "Orange", "Apple", "Mango"];
2fruits.includes("Mango")   // Returns true

1const fruits = ['apple', 'banana', 'mango', 'guava'];
2
3function checkAvailability(arr, val) {
4  return arr.some(arrVal => val === arrVal);
5}
6
7checkAvailability(fruits, 'kela');   // false
8checkAvailability(fruits, 'banana'); // true