Basic JavaScript

As soon as your computer loads a website on the internet, it sends a folder of files containing at least one html file. Javascript is the only client-side language which means it waits to execute code until it is on the computer, which is via a program called a browser.

This HTML file can be loaded from either the same folder or directly from the internet. There is a browser engine which is responsible for actually running the code. Along with displaying data and sending it to the server, the client-side code is responsible for changing the display.

Frameworks like react, angular, and vue, which build on top of Javascript, make writing client-side code a lot simpler and easier. Node uses the same v8 engine that Chrome uses, so it’s also lightning fast, but it’s still very performance intensive when it comes to writing APIs, talking to databases, or even communicating with other servers.

The language itself holds either primitives or compound data. Primitive data is usually numbers, booleans, or strings of text; compound data is held by arrays and objects. For declaring variables, we use the keywords let and const. If you plan to change the variable later, use let, otherwise use const. When we load a page, the document object contains many element objects through the dom. It is the most important object in Javascript, representing the structure of our html.