Array.prototype.includes () - JavaScript | MDN - MDN Web Docs
May 29, 2026 · The includes() method of Array instances determines whether an array includes a certain value among its entries, returning true or false as appropriate.
JavaScript Array includes () Method - W3Schools
Description The includes() method returns true if an array contains a specified value. The includes() method returns false if the value is not found. The includes() method is case sensitive.
How do I check if an array includes a value in JavaScript?
What is the most concise and efficient way to find out if a JavaScript array contains a value? This is the only way I know to do it: function contains(a, obj) { for (var i = 0; i < a.length;...
JavaScript Array includes() Method
This tutorial shows you how to use the JavaScript Array includes() method to check if an array contains a specified element.
Check if an array contains any element of another array in JavaScript
May 1, 2013 · 1402 Vanilla JS ... How it works some(..) checks each element of the array against a test function and returns true if any element of the array passes the test function, otherwise, it returns …
Array - JavaScript | MDN - MDN Web Docs
Feb 24, 2026 · JavaScript arrays are zero-indexed: the first element of an array is at index 0, the second is at index 1, and so on — and the last element is at the value of the array's length property minus 1. …
How to Check if an Array Contains a Value in Javascript
In this tutorial, you'll learn how to check if an array contains a value, either a primitive value or object, in JavaScript.
JavaScript Array includes () Method - GeeksforGeeks
Jan 16, 2026 · The includes () method in JavaScript is used to check whether an array contains a specific value. It returns a boolean result, making element checks simple and readable.
How to check if an array includes an object in JavaScript ?
Jul 11, 2025 · Check if an array includes an object in JavaScript, which refers to determining whether a specific object is present within an array. Since objects are compared by reference, various methods …
JavaScript Array Contains: 6 Methods to Find a Value | Built In
Jun 12, 2025 · Finding a value in an array is useful for effective data analysis. Learn how to discover what a JavaScript Array contains using indexOf, includes, for loop, some methods and more.