What Is JavaScript?


JS is a powerful tool that can be used on the client and server side to make your web pages more interactive. With JS, you can create animated images, add text to a page and refresh content on the fly. It also can be used to handle user input such as credit card data, or to display autocomplete suggestions as the user types in a search box.

JavaScript was initially created to make web pages “alive” by allowing developers to add programming codes that run when the page is open or when a particular event occurs. These programs are called “scripts” and can be written in the HTML code of a web page without needing to be compiled or prepared.

The main use of JavaScript is browser scripting, which is when a developer embeds JS within a web page. It is an interpreted language, which means it runs as soon as a web page is loaded by a user’s Internet browser.

When a web page is opened, the browser’s interpreter reads the JS code and finds where it can run it on the relevant HTML elements within that page. Then the JS travels through that element family tree or DOM to access, modify, add or delete those elements.

While JS can be used to build web applications, it’s primarily used for making web pages more interactive and engaging. This is where JS’s power shines, and why so many UI Frameworks are built with it, such as React, Angular, Vue, and Ember.

JS is non-blocking and offloads long-running tasks to a separate thread. This feature is useful when you want to execute a task like loading a file on a server, but you don’t want to block the browser from performing other actions.

JavaScript is also a powerful language for asynchronous interactions with remote servers. It can be used to automatically populate a form with information from a server, or to send emails or other messages when a specific action occurs on the page. It can also be used to create an autocomplete feature that will suggest relevant products based on the user’s intended search terms.

It is also an excellent language for building games and other applications that require high-performance functionality. It has a large number of libraries that make development even faster and easier.

There are a few different data types that are important to know when learning to program with JS. These include string, int, float, and date.

Variables are containers for values of any data type. They hold values such that when you use them, they have the value that you’ve declared in them.

The simplest way to learn to write JavaScript is to start with a simple script that does a basic operation, such as opening a file or sending a message. Then you can build on this to expand your knowledge and capabilities. When you’re ready to start working with more complex functions, consider a UI framework that is built around this language. These frameworks extend the capabilities of JS and simplify development by adding additional features and functionality. They are great for beginners and professionals alike, but it’s important to remember that there is always a learning curve when using a new library or framework.