What is JavaScript?


JavaScript is a popular programming language that’s used in web development, mobile development, and game development. It allows developers to implement dynamic features that can’t be done with HTML and CSS. It’s so versatile that it’s used on both client-side and server-side websites.

Its versatility also makes it ideal for creating applications, web browsers, hardware controls, and more. In fact, it’s the most used client-side language in the world, with 98% of websites using JavaScript on the client side as part of the webpage’s behavior.

What Would the Web Look Like Without JavaScript?

JavaScript was first developed in 1995 to make website pages more dynamic. It added simple effects, such as showing and hiding elements, but soon developers realized that it could do much more. It’s been used to add pop-up videos, interactive maps, and other features that can’t be implemented with other languages.

The most important thing about JavaScript is that it’s a native language to web browsers, which means that it will understand and execute the code on a visitor’s computer. This makes it a lot faster than other languages and more flexible.

You can find a list of JavaScript-enabled browsers here.

What is a JavaScript Engine?

A JavaScript engine is a software component that translates and executes a program’s JavaScript code. It does this by reading the script and converting it to machine code (commonly called “parsing” the code). Then it runs the compiled code on the machine to run it as fast as possible. The engine then optimizes the machine code based on its knowledge of what’s happening with it and the data that flows through it.

JS engines are a central feature of most modern browsers, and are typically found in the DOM, which is where all the elements on a page are located. These engines also manage the creation of an Abstract Syntax Tree that defines the script’s scope and structure.

The Abstract Syntax Tree is an abstract representation of how the script will work, and it’s a key to understanding how JS functions work. It’s a good idea to have some basic understanding of how this works, because it will help you better explain JS to others who don’t have experience with it yet.

What is a JavaScript Execution Context?

A JavaScript execution context is the set of objects that are created when a function is invoked. This context contains all the information that the function needs to do its job. It can include variables, function parameters, and a call stack, which is a way to keep track of the context’s existence.

When a function is called, it creates an execution context that includes all the things it will need to do its job. It also includes a call stack, which keeps track of the context’s location as the function is being executed.

In addition to creating an execution context, JavaScript also creates a memory map that stores all the information it needs to do its job. This includes the name of all the functions it has called and their arguments. Then, it assigns these variables to the appropriate memory locations.