My first ReactJS app from scratch

ReactJS is a JavaScript library for developing user interfaces (UIs) which efficiently update when your data changes

ReactJS apps are very performant since ReactJS uses a virtual DOM which is a JavaScript object representing the regular DOM. The virtual DOM is much faster than the regular DOM

To install ReactJS on your computer open a command line and type:

$ npm install -g create-react-app

Proceed to create a new ReactJS project:

$ create-react-app myProject

Change to the directory where you just created your new ReactJS project and type:

$ cd myProject

$ npm start

to launch the developer server and open your localhost on port 3000 i.e. (http://localhost:3000)

Today we are going to write a small ReactJS app with a + and – button to add and to substract 1 to a counter: