What is JavaScript?

JavaScript is a text-based programming language used both on the client-side and server-side that allows you to make web pages interactive. Where HTML and CSS are languages that give structure and style to web pages, JavaScript gives web pages interactive elements that engage a user. Common examples of JavaScript that you might use every day include the search box on Amazon, or refreshing your Twitter feed, Linkedin, search box of google, etc.

Incorporating JavaScript improves the user experience of the web page by converting it from a static page into an interactive one. To recap, JavaScript adds behavior to web pages.

What is JavaScript used for?

JavaScript is mainly used for web-based applications and web browsers. But JavaScript is also used beyond the Web in software, servers and embedded hardware controls. Here are some basic things JavaScript is used for:

1. Adding interactive behavior to web pages

JavaScript allows users to interact with web pages. There are almost no limits to the things you can do with JavaScript on a web page — these are just a few examples:

  • Show or hide more information with the click of a button
  • Change the color of a button when the mouse hovers over it
  • Zooming in or zooming out on an image
  • Displaying a timer or count-down on a website
  • Playing audio and video in a web page
  • Displaying animations

2. Creating web and mobile apps

Developers can use various JavaScript frameworks for developing and building web and mobile apps. JavaScript frameworks are collections of JavaScript code libraries that provide developers with pre-written code to use for routine programming features and tasks — literally a framework to build websites or web applications around.

Popular JavaScript front-end frameworks include React, React Native, Angular, and Vue. Many companies use Node.js, a JavaScript runtime environment built on Google Chrome’s JavaScript V8 engine. A few famous examples include Paypal, LinkedIn, Netflix, and Uber!

3. Building web servers and developing server applications

Beyond websites and apps, developers can also use JavaScript to build simple web servers and develop the back-end infrastructure using Node.js.

Some of the Frameworks of JS:

  • Angular JS
  • Node JS
  • React JS
  • Vue JS

Lets see how one of the best professional Social site switch to one of the framework of JS and how it was benefited!!

The server side of the LinkedIn mobile app was built by using Node.JS. They actually moved the back end of the mobile application from Ruby on Rails to Node. Two key reasons for this switch were efficient performance and scalability.

The Ruby on Rails app was a synchronous app that the clients used to make several calls for a single page. All of the calls occurred sequentially, with each thread handling a single request.

Node.JS allowed LinkedIn developers to move to an asynchronous event system where the client made a single request per page and things started working fast and smooth.

The result after applying the in place ofwere:

  • The company now uses 4 servers instead of 15.
  • The traffic capacity has doubled.
  • On the client side, the app works 2 to 10 times faster.