Array.prototype.includes() in Javascript – ECMAScript 2016 (ES7)

The Array.prototype.includes() method in JavaScript checks whether an array contains a specific value and returns a boolean value indicating whether the value is present or not.

Syntax:

array.includes(valueToFind[, fromIndex]);

• valueToFind – The value to search for in the array.
• fromIndex (Optional) – The index from which to start searching for the value in the array. If the value is not found after the specified index, the method returns false. If omitted, the default value is 0.

Return value:

• true if the array contains the value, false otherwise.

Example:

const array1 = [1, 2, 3, 4, 5];
console.log(array1.includes(2));     // true
console.log(array1.includes(6));     // false
console.log(array1.includes(4, 3));  // true 
console.log(array1.includes(4, 4));  // false

In the above example, array array1 is checked whether 2, 6, 4 is present in it or not, with and without fromIndex.