Inheritance in Javascript.

class-js.js

(function(window) {
    window.ClassJS = {
        extend: extend,
        clone: clone
    };
    
    function extend(subClass, superClass) {
        function F() {}
        F.prototype = superClass.prototype;
        subClass.prototype = new F();
        subClass._super_ = superClass.prototype;
        subClass.constructor = subClass;
        
        if(superClass.prototype.constructor == Object.prototype.constructor) {
            superClass.prototype.constructor = superClass;
        }
    }

    function clone(baseClass) {
        function F() {}
        F.prototype = baseClass;
        return new F;
    }    
})(window);

classical-inheritance.js

/*
* Classical Class inheritance
*/
'use strict';

function SuperClass(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName
    this.jedi = false;
}

SuperClass.prototype.getFullName = function() {
    console.log('I am from Super ' + this.firstName + ' ' + this.lastName);
};


function ChildClass(firstName, lastName) {
    ChildClass._super_.constructor.call(this, firstName, lastName);
    
    this.jedi = true;
}

ClassJS.extend(ChildClass, SuperClass);

ChildClass.prototype.getFullName = function() {
    ChildClass._super_.getFullName.call(this);
    
    console.log('I am from child class ' + this.firstName + ' ' + this.lastName + ' Jedi: ' + this.jedi);
};


var child = new ChildClass('Luke', 'Skywalker');
child.getFullName();

prototype-inheritance.js

/*
* Prototype inheritance.
*/
'use strict';

var SuperClass = {
    constructor: function(firstName, lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.jedi = false;
    },
    getFullName: function() {
        console.log('I am from Super ' + this.firstName + ' ' + this.lastName);
    }
};

var ChildClass = ClassJS.clone(SuperClass);

ChildClass.constructor = function(firstName, lastName) {    
    ChildClass.__proto__.constructor(firstName, lastName);
    this.jedi = true;
};

ChildClass.getFullName = function() {
    ChildClass.__proto__.getFullName();
    console.log('I am from child class ' + this.firstName + ' ' + this.lastName + ' Jedi: ' + this.jedi);
};

var child = ClassJS.clone(ChildClass);
child.constructor('Luke' , 'Skywalker');
child.getFullName();