In this chapter we look at one way of storing more than one value in a variable: arrays.

In the last chapter, we worked with numbers. In this chapter, we’ll work with text and write our first applications.

In this chapter, we take the very first steps with JavaScript and learn about numbers, variables and functions.

This blog post provides an overview of my new series of blog posts called “Learning web development”.

On 25 June 2025, the 129th Ecma General Assembly approved the ECMAScript 2025 language specification (press release, GitHub release), which means that it’s officially a standard now.

This blog post explains what’s new.

In this blog post, we explore ways in which we can make regular expressions easier to use.

JavaScript has two common patterns:

• Maps: We check the existence of a key via .has() before retrieving the associated value via .get().
• Arrays: We check the length of an Array before performing an indexed access.

These patterns don’t work as well in TypeScript. This blog post explains why and presents alternatives.

In ECMAScript 2025, JavaScript gets a class Iterator with iterator helper methods. This class conflicts with TypeScript’s existing types for iterators. In this blog post, we explore why that is and how TypeScript solves that conflict.

In this blog post, we explore how we can style text that we log to the console in Node.js.

Some of the examples use a Unix shell but most of the code should also work on Windows.

Converting values to strings in JavaScript is more complicated than it might seem:

• Most approaches have values they can’t handle.
• We don’t always see all of the data.