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.
Advantages of JavaScript
- Speed — JavaScript tends to be very fast because it is often run immediately within the client’s browser. So long as it doesn’t require outside resources, JavaScript isn’t slowed down by calls to a backend server. Also, major browsers all support JIT (just in time) compilation for JavaScript, meaning that there’s no need to compile the code before running it.
- Simplicity — JavaScript’s syntax was inspired by Java’s and is relatively easy to learn compared to other popular languages like C++.
- Popularity — JavaScript is everywhere on the web, and with the advent of Node.js, is increasingly used on the backend. There are countless resources to learn JavaScript. Both StackOverflow and GitHub show an increasing amount of projects that use JavaScript, and the traction it’s gained in recent years is only expected to increase.
- Interoperability — Unlike PHP or other scripting languages, JavaScript can be inserted into any web page. JavaScript can be used in many different kinds of applications because of support in other languages like Pearl and PHP.
- Server Load — JavaScript is client-side, so it reduces the demand on servers overall, and simple applications may not need a server at all.
- Rich interfaces — JavaScript can be used to create features like drag and drop and components such as sliders, all of which greatly enhance the user interface and experience of a site.
- Extended Functionality — Developers can extend the functionality of web pages by writing snippets of JavaScript for third party add-ons like Greasemonkey.
- Versatility — There are many ways to use JavaScript through Node.js servers. If you were to bootstrap Node.js with Express, use a document database like MongoDB, and use JavaScript on the frontend for clients, it is possible to develop an entire JavaScript app from front to back using only JavaScript.
Why Millions of Developers use JavaScript for Web Application Development
JavaScript is a client-side programming language which helps web developer to do Web Application Development and make dynamic and interactive web pages by implementing custom client-side scripts. Developers can also use cross-platform runtime engines like Node.js to write server-side code in JavaScript. Developers can also create web pages that works well across various browsers, platforms, and devices by combining JavaScript, HTML5, and CSS3.
There are many JavaScript Frameworks available in the web market like AngularJS, ReactJS, NodeJS, etc. By using these frameworks, you can reduce the amount of time and efforts required for developing JS-based sites and apps. JavaScript allows programmers to build large-scale web applications easily. It simplifies the whole process of developing large-scale web applications.
How JS is beneficial to some of the top companies?
Microsoft
Microsoft needs to work closely with JavaScript to built its Edge web browser. All browsers need to process and execute JavaScript efficiently, so Microsoft has developed and maintains its own JavaScript engine for Edge. Actually, there has been talk of them creating an alternate version of NodeJS with the Edge engine.
Recently, Microsoft has really embraced NodeJS. They thoroughly support Node on the Azure cloud platform. It's one of Azure’s major features, and they’ve integrated Visual Studio support for Node.
Microsoft has also developed a version of Node for Internet Of Things(IoT) applications. NodeJS is great for IoT because it’s lightweight and efficient.
PayPal
PayPal has obviously been using JavaScript on the front end of their website for a long time, but that’s only the beginning.
The online payment giant was one of the earliest adopters of NodeJS. During an overhaul of their account overview page, they decided to try building the page in Node at the same time as their usual Java development. The NodeJS version worked out so well, that they chose to use it in production and build all client-facing applications in Node going forward. That means that most of what you see in your account is running on Node.
PayPal even went as far as to create and maintain their own version of Express, called KrakenJS. It’s pretty obvious that they like JavaScript over at PayPal.
Uber
Uber needs to handle loads of data in real-time. They have millions of requests coming in continuously, and that’s not just hits on a page. Uber needs to track driver locations, rider locations, and incoming ride requests. It has to seamlessly sort that data and match riders as fast as possible.
All of that plays to NodeJS’s and JavaScript’s strengths. Node is designed to handle requests and handoff data quickly. It’s asynchronous capabilities are a huge part of that. Node is central to Uber’s user-facing stack for just that reason.
How doesn’t Google use JavaScript? Seriously, it’s everywhere. Google’s search results spring up as your typing get there with JavaScript. The Gmail web client is powered by JavaScript. Google Docs? Yeah, that’s JavaScript too.
Google develops and usually open sources it’s own JavaScript tools. The most obvious example is AngularJS. Angular is used most prominently in Google’s DoubleClick advertising platform, but it’s also one of the most popular front end frameworks available. It’s even part of the MEAN stack.
Google’s more intensive services, like Google Docs, use Closure Tools. This set of tools compiles JavaScript into a lower-level faster form more suited for rich and highly responsive web applications.
There’s another big point to touch on. Google developed Chrome. Chrome, being a web browser, needed a JavaScript engine, so Google also made V8. V8 not only powers Chrome, it’s at the heart of NodeJS. So, without Google, there would be no Node.
Netflix
Like PayPal, Netflix started out using Java for just about everything. They too ran into problems with Java’s size and the time it required to develop.
Over time, Netflix moved away from its more traditional structure into the cloud and started to introduce NodeJS. With Node, Netflix was able to break down pieces of their user interface into individual services. This more distributed approach was able to speed things up and alleviate stress on their servers. Today, a large portion of Netflix’s interface is running on Node.