What is ReactJS ? Why we use It?

source: Reactjs.org

The core objective of ReactJS is to provide the best possible rendering performance. Its strength comes from the focus on UI and components. Instead of working on the entire web app, ReactJS allows a developer to break down the complex UI into simpler components.
It is an Open source library for building user interfaces, Not a framework.

Why learn React ?
- Created and maintained by Facebook
- More than 100k stars on Github
- Huge community
- In demand skillset
- Most loved web framework 74.5%
- Usually have a higher salary than others
- React beats both categories, with 64.8% saying they would use it again, compared to 28.8% for Vue and 23.9 for Angular

Uses of ReactJS -

Earlier people used to write code in angular, but that is much complex and has to maintain different files for a single component. So developers want something which is very easy to work on as well as scalable and efficient also.

Then ReactJS came as a life savior as it provides us to focus on a single component and write HTML inside it in the form of JSX (syntactic sugar).

Today ReactJS become one of the most popular frameworks and developers started loving it because of simplicity and flexibility.

One reason for its popularity is because many big tech giants are using it, and its performance is seamless so others also opting it. That’s why it is becoming popular.

The State makes it possible to store all the changes in one section. When using ReactJS, developers take all the content that can change during the application and place it in a single location (State).

The Props make it possible to populate components using custom data.

Components allow developers to break down complex UI. The idea of components is what makes ReactJS unique.

Pros of ReactJs —
- Virtual Dom
- Seo Friendly
- Reusable Components
- Easy Data flow
- Easy debugging & testing
- Easy to manage State
- Easy to work on different module at a time

Cons of ReactJs
- Takes time to develop it
- Improper Documentation

Prerequisites
HTML,
CSS,
JS fundamentals
ES6
Javascript — ‘this’ keyword, filter, map and reduce
ES6- let & const, arrow functions, template literals, default parameters, object literals, rest and spread operator and destructuring assisgnment