A Needle In The Haystack Codewars Javascript

Javascript Programming

Have you ever heard of the coding platform called Codewars? It’s a place where developers of all skill levels can challenge themselves by solving coding problems. One particular problem that caught my attention is called “A Needle in the Haystack”. In this article, I want to share my personal experience and deep dive into the details of solving this problem using JavaScript.

Introduction to the Problem

The “A Needle in the Haystack” problem on Codewars challenges us to find the index of a specific word, represented by the needle, within an array of words, represented by the haystack. This may seem like a simple task at first, but as we dig deeper, we will find some interesting aspects to consider.

Understanding the Input

Before we start solving the problem, let’s understand the input and constraints. The haystack array can contain any number of words, and each word can have any combination of characters. The needle is a single word that we need to search for within the haystack. We are asked to return the index of the needle within the haystack.

Solving the Problem

To solve the “A Needle in the Haystack” problem, we can utilize JavaScript’s built-in array methods. One approach is to use the indexOf() method, which returns the index of the first occurrence of a specified element in an array.

Here’s the code:

function findNeedle(haystack, needle) {
return haystack.indexOf(needle);

With just a single line of code, we are able to solve the problem. The indexOf() method searches for the first occurrence of the needle within the haystack and returns its index. If the needle is not found, the method returns -1.

Testing Our Solution

When solving coding problems, it’s crucial to test our solution with various test cases to ensure its correctness and efficiency. Let’s test our solution with some examples:

  • findNeedle(["apple", "banana", "orange", "needle"], "needle"); should return 3
  • findNeedle(["cat", "dog", "bird", "horse"], "bird"); should return 2
  • findNeedle(["tree", "car", "house"], "apple"); should return -1

By running these test cases, we can verify that our solution is working correctly.


In this article, we explored the “A Needle in the Haystack” problem on Codewars and dived deep into solving it using JavaScript. We learned that by utilizing the indexOf() method, we can easily find the index of a specific word within an array. Testing our solution gave us confidence in its correctness and efficiency.

Codewars is a great platform to challenge ourselves and improve our coding skills. So, next time you come across the “A Needle in the Haystack” problem or any other problem on Codewars, give it a try and see how well you can find that needle in the haystack!