JavaScript - Engine & Runtime

Overview

Estimated time: 10–15 minutes

JavaScript engines (like V8, SpiderMonkey) execute code, while runtimes (like browsers, Node.js) provide APIs and environment.

Learning Objectives

• Understand the difference between engines and runtimes.
• Know how JavaScript is executed in different environments.

Prerequisites

• JavaScript - Package Manager (npm/yarn/pnpm)

JavaScript Engines

- V8 (Chrome, Node.js)
- SpiderMonkey (Firefox)
- JavaScriptCore (Safari)

Runtimes

- Browsers: provide DOM, BOM, and Web APIs
- Node.js: provides file system, process, and other APIs

Common Pitfalls

• Not all APIs are available in every runtime.

Summary

Understanding engines and runtimes helps you write portable, efficient JavaScript code.