What Is JavaScript?


JavaScript is a scripting language that controls the dynamic elements of web pages. It is supported by most modern web browsers and works on both desktop and mobile devices. It is also a good choice for creating server-side or client-side applications because it’s platform independent and offers several libraries that are useful in building both types of software.

How It Works

The JavaScript code is interpreted by the web browser engine, which then creates an Abstract Syntax Tree (AST) and submits it for execution. The AST is then transformed into machine code by a JavaScript compiler, which is usually done in real time (just-in-time) to increase performance.

It then gets translated into a byte code that is submitted to the Execution Stack (Call Stack), which then executes the script. This process can take a while, so it’s important to use the newest version of the JavaScript engine for the best results.

Variables and Strings

In a JavaScript program, variables are usually named something like myVariable, but you can name them almost anything you want. However, there are some limitations – for example, you cannot use the same variable name twice, and you can’t have variables of different types. The syntax of variables can be a bit confusing, so it’s best to check out the naming rules on this website to learn how to avoid any common mistakes.

Variables are case sensitive, so make sure your code matches the variable’s name. You can also use special keywords for a specific type of value, such as true or false.

When writing a JavaScript program, you can use many functions and methods to manipulate data. For instance, you can get the contents of a text box by reading the text of the box and comparing it with the value of the textContent property on the same object. You can also use conditional operators and loops to test for and evaluate conditions in your code.

Using Web APIs

The most popular way to implement JavaScript is by using Web APIs, which provide a way to call services on the Internet. These services can be used for things like data processing and rendering graphics.

These services can be called from the JavaScript code in your program, and the results are returned to your script. The result can be a stream of events, or just a single response.

A web browser is an application that runs in a computer, usually on a local server, which receives and renders content from the Internet. This includes websites, apps and other digital content.

There are many ways to interact with these services, but one of the most common is by creating a web page that contains a JavaScript engine. This is usually a standalone program that can be embedded in the web page or website, or can run outside of the browser on the server.

Creating Web Apps with JavaScript

JavaScript is an excellent choice for developing client-side web applications, as it allows you to control the dynamic elements of a web page. This includes the text, images, and animations on the page. It’s also a lightweight, cross-platform language that doesn’t consume a lot of CPU or RAM resources. It’s one of the most commonly used languages in web development, and it can help you build more interactive, functional pages for your website.