Check if a value exists in an array using Javascript.

December 18, 2020

In this article, I will show you the 2 ways for checking if a value exists in an array.

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1. Using includes()

This method returns true if the array includes the value, else it returns false.

let array = ["a", "b", "c", "d"];
console.log(array.includes("b")); // true
console.log(array.includes("e")); // false

2. Using indexOf()

This methods returns the index of the value if it exists, else it returns -1.

let array = ["a", "b", "c", "d"];
console.log(array.indexOf("b")); // 1
console.log(array.indexOf("e")); // -1

Written by Murtaja Ziad, a full-stack web developer.
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