Functions are first-class citizens in JavaScript. That's why you will early on hear about callback functions in JavaScript, which are a super powerful asset when writing JavaScript code. Here I want to give you a brief introduction to them. Callback functions are usually passed as argument to functions: In this case, our printText function takes…
There are two error handling scenarios in JavaScript. Either an error is thrown from a third-party (e.g. library, database, API) or you want to throw an error yourself. While you have the error at your hands for the former, for the latter you need to new it yourself: Sometimes you want to throw custom errors though. I learned that you can create…
When you have learned about JavaScript promises for the first time, you learned about the promise's methods then and catch. While the former's callback function is called whenever a JavaScript promise resolves successfully, the latter is used for error handling: Eventually you have learned about async/await in JavaScript as alternative to a…
I have always been of the understanding there are no common sense rules about how to create a minimal Node.js application with Babel. In my search for these answers, it seemed that every tutorial I came across showed something different. As a result, I wanted to streamline this project setup for my readers and myself, so I developed a common…
In JavaScript ES6, you can import and export functionalities from modules. These can be functions, classes, components, constants, essentially anything you can assign to a JavaScript variable . Modules can be single files or whole folders with one index file as entry point. The import and export statements in JavaScript help you to share code…
The content of this section is a crash course in node and npm. It is not exhaustive, but it will cover all of the necessary tools. The node package manager (npm) installs external node packages (libraries) from the command line. These packages can be a set of utility functions, libraries, or whole frameworks, and they are the dependencies of your…
In every programming language, you will find variables. This also holds true for JavaScript. Essentially variables are used to carry information. Without them, it wouldn't be really possible to code any applications. At some point in time, you always have to keep or transfer information in variables. In this JavaScript tutorial, I want to dive with…
Just recently I had to apply Webpack's Code Splitting, because the bundle size of a single file for my JavaScript library got too big when installing and importing it in another JavaScript project. After going through the process of Code Splitting my library, I was able to reduce my bundle size significantly by not importing the whole library at…
Every once in a while we need to test API requests. Axios is one of the most popular JavaScript libraries to fetch data from remote APIs . Hence, we will use Axios for our data fetching example -- however, the following tutorial should make it possible to exchange axios with any other data fetching library. In this data fetching example with…
A JavaScript naming conventions introduction by example -- which gives you the common sense when it comes to naming variables, functions, classes or components in JavaScript. No one is enforcing these naming convention rules, however, they are widely accepted as a standard in the JS community. JavaScript Naming Conventions: Variables JavaScript…
