JavaScriptOO.js

var Person = function(p) {
    this.firstName = p.firstName;
    this.lastName = p.lastName;
    this.age = p.age;

    this.setFirstName = function(name){
        if(typeof name != 'string'){
            throw ': NameError: Hey my should be a proper name man!';
        }
        else {
            this.firstName = name;
        }
    }
};

Person.prototype = {
    introduce : function(){
        console.log('Hi there, I am ' + this.firstName + ' ' + this.lastName);
    }
};

Person.prototype.canDrive = function(){
    if(this.age <= 18){
        console.log('Nope');
    }
    else{
        console.log('Definitely!');
    }
};

var Child = function(child){
    Person.call(this,{
        firstName:  child.firstName,
        lastName:   child.lastName,
        age :       child.age
    });
};

// Creating a Child.prototype object that inherits from Person
Child.prototype = Object.create(Person.prototype);
Child.prototype.constructor = Child;

Child.prototype.setParent = function(person){
    this._parent = person;
};

Child.prototype.introduceParent = function(){
    console.log(this._parent.introduce());
    console.log(this.firstName);
};

// Creating a new person object
person = {
    firstName: 'Bhargav',
    lastName:  'Voleti',
    age:        22
};

var bhargav = new Person(person);

bhargav.introduce();
bhargav.canDrive();
bhargav.setFirstName('bIgB');
bhargav.introduce();

var joe = new Child({
    firstName: 'Joe',
    lastName: 'Doe',
    age: 43
});

joe.introduce();
joe.setParent(bhargav);
joe.introduceParent();