Event Module in NodeJS (Core Module in NodeJS)

 Why We use Event module in Nodejs ?

Important for  example - When user registered we want to many work for user like as store in database, send welcome mail and many work it will help you to do all the things in very good manner  

How to use it 

const emmiter = require('event'); it will return class then 

const myemmiter = new emmiter(); convert into object 

Create Event listener 

myemmiter.on('greeting',(data)=>{

    console.log("welcome to OffSection India ",data);

})

greeting= Event name 

data = recving data from emit 

Emit or Call event listener 

myemmiter.emit('greeting','AshutoshKumar');

in this emit greeting is event name and Ashutoshkumar is data 

One Real World Example

When we require a student to add database and send mail and welcome massage we use this for all .

const emmiter = require('events');

//Creating Class

class registered extends emmiter {

         registerd(username){

            console.log(`You are successfully Registered `)

            //calling event

            this.emit('registered',username);

         }

}

//making Object

const Registered = new registered();

//listen event for add to data base

Registered.on('registered',(data)=>{

         console.log(`Hey Mr/Mrs ${data}\nYou are successfully

Added to our DataBase`);

})

//listen event for welcome massage

Registered.on('registered',(data)=>{

         console.log(`Hey Mr/Mrs ${data}\nWelcome Come To Our Company`);

})

//listen event send password to email

Registered.on('registered',(data)=>{

         console.log(`Hey Mr/Mrs ${data}\nplease Check Your mail For

Password and Username`);

})

//calling object function

Registered.registerd('Ashutosh Kumar');