In this chapter we explore two topics:

• A shell is like browser console, but for the operating system instead of for JavaScript. It helps us with programming by running the tools (programs) we need to get things done.
• Node.js is a program that lets us run JavaScript code outside browsers – which we can use for a variety of things.

In this chapter, we learn how to do things repeatedly in JavaScript.

In this chapter, we learn about tools for only running a piece of code if a condition is met: truth values (booleans), comparisons and if statements.

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.