Inheriting From The Event Emitter - Part 2

The code

var EventEmitter = require('events');
var util = require('util');

function Greetr() {
    EventEmitter.call(this);
    this.greeting = 'Hello world!';
}

util.inherits(Greetr, EventEmitter);

Greetr.prototype.greet = function(data) {
    console.log(this.greeting + ': ' + data);
    this.emit('greet', data);
}

var greeter1 = new Greetr();

greeter1.on('greet', function(data) {
    console.log('Someone greeted!: ' + data);
});

greeter1.greet('Tony');

• Notice the call()

var util = require('util');

function Person() {
    this.firstname = 'John';
    this.lastname = 'Doe';
}

Person.prototype.greet = function() {
    console.log('Hello ' + this.firstname + ' ' + this.lastname);
}

function Policeman() {
    Person.call(this);
    this.badgenumber = '1234';
}

util.inherits(Policeman, Person);
var officer = new Policeman();
officer.greet();