Preliminaries

The Language Guides are a short reference for programmers who already know how to program and want to learn JavaScript quickly. They assume you are comfortable with variables, control flow, functions, and basic object-oriented programming in another language, such as Python, Java, C++, or C#, and they focus on the syntax and core concepts of the language rather than programming fundamentals.

This chapter covers where JavaScript came from, how it works as a language and a runtime, and how to set up your environment to write and run it. The Language Guides as a whole are organized by programming paradigm, so you can read them from the beginning, jump to a specific topic, or use them as a reference when you need to look something up.

Learning Outcomes

  • Explain where JavaScript came from and how it relates to ECMAScript standardization
  • Describe JavaScript’s core characteristics as a language, including its typing and execution model
  • Explain how JavaScript engines and runtimes execute code, including the event loop
  • Set up a working Node.js and VS Code environment for writing and running JavaScript

Sections

  1. A Brief History of JavaScript
  2. JavaScript as a Language
  3. How JavaScript Works
  4. Setting Up Your Environment