JavaScript: Crash Course Part 1

Introduction

JavaScript is the lingua franca of the web - it's used universally by every website out there and has grown from a simple scripting language to a mature programming language with an enormous ecosystem. Today we'll learn basic JavaScript syntax, data types, and functions.

Getting Started

Getting started with JavaScript is easy - all you need is a web browser. We will be using some particular features that aren't supported by older browsers, so we recommend using the latest version of Google Chrome.

Every modern web browser (e.g. Chrome, Firefox, Edge, and Safari) includes something called a Web Console which you can use to interactively execute JavaScript in the context of the current page. To open up the Web Console, right-click anywhere on the current page and select Inspect from the menu (you can also type Control+Shift+I on Windows or Cmd+Option+K on Mac). Then select the Console tab in the window that pops up.

You can type any valid JavaScript in this window and press enter to execute it - what's more, you can view variables and objects in the context of the current page. This can be very useful if the current page is running a script that you want to debug!