The every() method in JavaScript lets us do logical tests on every member of an array. Let’s look at how it works. — Sometimes with arrays, we want to test every element for a certain condition. While individual conditions can be tested easily with an if statement, it becomes a little trickier with multiple array elements. As such, JavaScript provides a method on arrays called every which will test every element for a…

Universally Unique Identifiers are an easy way to reference various objects and elements in JavaScript. Let’s look at how to make them. — Universally Unique Identifiers (UUIDs) are used all over the place in software development for everything from identifying object elements to DOM elements on a web page. They are unique, 128 bit identifiers consisting of 36 characters in the format 8-4-4-4-12 - for example, f81e7af3-fcf4-4cdd-b3a3-14a8087aa191. UUIDs typically do not rely on…

The concat() method is used to return shallow copies of merged arrays. Shallow copies contain the same reference as the original array sliced. — The concat method on arrays is used to take two arrays and concatenate them into one. It takes as many arrays as you like - so you can concatenate many arrays at once: Array.concat(value1, value2, value3, ...valueN) Each item added to the concat method must be of type array. Let's…

How to check if an array is a subset of another array? Find out in this guide. — There are many use cases where knowing if an array is a subset of another can be quite useful — and although usually immediately obvious to the human eye, it can be difficult to evaluate in code. In the code below, arr2 is a subset of arr1, but arr3 is…

When we add ordinal suffixes to a number, it can differ by country, language, and locale. Let’s look at a way to reliably accomplish this. — In Javascript it’s usually considered best practice to work with absolute numbers, as number is a defined type. However, when expressing these numbers in user interfaces, it's more likely we'll want to express them differently. For example, consider I have the following list of numbers. …

It’s one of the most common operations we do in JavaScript, and there are a bunch of ways to do it. Let’s compare. — One of the most frequent operations we perform on an array is removing the last element. There are a few different ways to do this — but one of the most common is to use the pop() method. Consider you have the following array: let myArr = [ "🍎", "🍏"…

There are so many ways to iterate over something in JavaScript, but what do they all mean? — There are quite a few ways in Javascript to loop through an array of items or any other iterable item in Javascript. You may have seen them: arr.forEach() for(let item of arr) for(let item in arr) for(let item = 0; item < arr.length; ++item) This may seem like a lot…