React is a JavaScript library for building user interfaces, which allows you to build single-page applications. It was inspired by the idea that views should be simple and declarative, with responsibilities separated. In this blog article, we will learn what Reactjs (or simply React or Reactjs) is and why we should use Reactjs instead of other JavaScript frameworks like Angular

What is React.JS?

React is an open-source JavaScript library that renders HTML and provides a flexible view layer along with some sophisticated state management. It manages the view layer, manipulating DOM components like lists, cards and menus in real-time. React was first created by Jordan Walke, a software engineer working for Facebook. React was first deployed on Facebook’s newsfeed in 2011 and on Instagram in 2012.

React allows developers to create large, rich interactive applications. Unlike other frameworks or libraries, it is highly reactive and stateful, so you can easily handle multiple views at the same time, interact with them and send updates back to the server. The main purpose of React is to be fast, scalable, and simple. It works only on user interfaces in the application. This corresponds to the view in the MVC template.

Features React.JS offers?

React.js properties include the following-

• React.js is declarative

• React.js is simple

• React.js is component-based

• React.js supports server-side

• React.js is extensive

• React.js is fast

• React.js is easy to learn

JSX

Instead of using JavaScript to render the web pages with templating, React provides JSX. JSX is a simple JavaScript that allows HTML quoting and uses these HTML tag syntax to render subcomponents. The interpreter then converts the HTML into JavaScript code calls. We can also write in pure old JavaScript as well.

React Native

React Native allows you to build native mobile apps for iOS and Android using the same JavaScript as web apps. It uses the same core UI building blocks as regular iOS and Android apps, allowing you to easily adapt components written in Objective-C, Java, or Swift.

Single Way data flow

Properties flow down and actions flow up. This means that each component calls property-getter functions and renders a property passing down to render the output. The React apis are built on this concept where view layer can modify its data but it does not need to do any changes to the state itself. There is no need for every component to create its state, we only create components which need state modification. For example, component only needs to have focusable and blurable properties. It doesn’t need any other properties or behaviour like click, focus and so on even though these things might be needed further down along with other components who require them.

Virtual Document Object Model

React has a special feature that enables the programmer to code as if the whole page is rendered on each change. The React library only renders components that actually change.

Why React.JS?

Why should you use React? The main reason is that there isn’t a better choice out there. React is fast, scalable and developer friendly. The other reason to choose React over other frameworks is the availability of many features that are not available in other frameworks like Angular, Vue or Backbone etc.

1. Simplicity

React is one of the most popular JavaScript frameworks for building web and mobile applications. It is based on a component-based approach, a well-defined lifecycle, and the use of just plain JavaScript. React uses a special syntax called JSX which allows you to mix HTML with JavaScript. Developers can still write in plain JavaScript but JSX is much easier to use.

2. Easy to Learn

Front-end development means programming in HTML, CSS and JavaScript. React is an open-source framework that makes a whole new way of building user interfaces: instead of building pages from scratch, you assemble reusable components that interact with each other. React is easy to learn, highly efficient and fast. Even advanced features like animations are built into the core library so that you can focus on your application’s unique experience instead of writing the same code again and again.

3. Native Approach

React is a JavaScript library that can be used to create mobile applications. With React, we can create both web and IOS (and Android) applications at the same time, due to the elaborate code reusability in React. React also supports stateless functional components

4. Data Binding

React uses one-way data binding and an application architecture called Flux controls the flow of data to components through one control point – the dispatcher. It's easier to debug self-contained components of large ReactJS apps.

5. Performance

React does not offer any concept of a built-in container for dependency. You can use Browserify, Require JS, EcmaScript 6 modules which we can use via Babel, ReactJS-di to inject dependencies automatically.

6. Testability

ReactJS applications are super easy to test. React views can be treated as functions of the state, so we can manipulate with the state we pass to the ReactJS view and take a look at the output and triggered actions, events, functions, etc.