What is JavaScript?

javascript is a full-fledged programming language that, when applied to HTML, can give websites dynamic interactivity. It can be used to underline a typo in an article, make a button clickable or create a slideshow of images. It’s also responsible for the real-time content updates on your favorite sites and apps like Google, Facebook, Amazon, Reddit, YouTube, and many others. In addition, it’s the underlying technology behind autocomplete text suggestions and 2D/3D animations of images and videos.

JavaScript is a client-side scripting language, which means that it runs inside the web browser (the client) and is therefore accessed directly by the user. This makes it a very powerful tool for adding automation and interactivity to websites without the need for a server-side application.

It features a runtime system based on a small number of data types that represent numeric, Boolean and string values. It uses a prototype-based object model instead of the more common class-based system, which gives it the ability to use dynamic inheritance where what is inherited can vary for each object. In addition, it supports functions that are essentially loosely-typed methods and execute in the context of the current object (similar to PHP).

One of the most important things to understand about javascript is its event-driven nature. This is because it’s a scripting language, meaning it relies on events to take action. For example, when a user interacts with a button on the website, an event listener will execute and log the interaction to a console.

Another key component of javascript is its support for async functions and the await keyword, which allows you to write asynchronous code that behaves synchronously. This is especially useful when developing web applications that are scalable and can support large numbers of users.

Lastly, javascript is built on top of the Document Object Model (DOM), which enables you to access and manipulate web page elements such as HTML document objects, styles, and fonts. This means that you can easily add the rich interactivity and automation features that make modern websites and apps a delight to browse and use.

JavaScript has become the dominant language for creating interactive, automated web content. It’s the reason why websites like Reddit, Instagram, and Twitter can offer you real-time information and 2D/3D animations, as well as interactive maps, social feeds, and video galleries. It’s even responsible for the scrolling feature on the Google search page and the dynamic recommendations you see when typing a question into the search box at the bottom of the screen. It’s no wonder that javascript is the world’s most popular programming language, and it has become an integral part of every modern browser.