find() vs. filter() considering semantics

2023-07-26

Introduction

Imagine you're a JavaScript developer trying to write code that finds a specific item within an array. In the world of JavaScript, there are a few ways to search through arrays, and two popular methods are filter() and find(). But which one is better for your task? That's what we'll explore in this article.

Reasons to use find()

When your goal is to get just one result, using find() is more suitable.

Firstly, it offers clearer semantics.

As explained by Mozilla, the find() method is a feature of arrays in JavaScript that retrieves the first matching element from a given array. On the other hand, the filter() method creates a new array by checking through an existing array and selecting the elements that pass a certain test.

Why does this matter? Well, find() focuses on locating the first single matching element, whereas filter() is designed to extract multiple elements that meet a certain condition. So, if your aim is to find a single item, find() is the better choice.

Secondly, it's more straightforward to read.

Another reason to use find() is that it returns a single value, whereas filter() gives you an entire array. This difference has a meaningful impact on how your colleagues perceive and understand your code.

Take a look at this code snippet:

javascript code:

const items = [1, 2, 3, 4];
const filteredItem = items.filter(el => el === 2);

console.log(filteredItem); // [2]
console.log(filteredItem[0]); // 2

const foundItem = items.find(el => el === 2);
console.log(foundItem); // 2

In this example, the filter() method results in an array. This means that if you're looking for a single result, you need to do extra work like using [0] to access the value. Plus, your colleagues might become curious about other values at indices [1], [2], and so forth.

On the flip side, the find() method directly provides a single value. This approach simplifies the process and makes your code easier to understand.

Conclusion

In conclusion, when you're on the hunt for a lone item within an array, the find() method is good choice. Its clear meaning and simplicity make it the better choice for obtaining a single result in your JavaScript projects.