OOPS in Javascript

//prototype function

//1st approach

function Employee(name){

this.name=name;

}

Employee.prototype.getName = function(){

return this.name;

}

var e1 = new Employee("jitendra");

var e2 = new Employee("Raju");

console.log(e1.getName()); //Jitendra

console.log(e2.getName()); //Raju

//2nd approach

function Employee(name){

this.name=name;

}

Employee.prototype.getName = function(){

return this.name;

}

function getEmployeeDetails(){

//Overriding getName

Employee.prototype.getName = function(){

return this.name.toUpperCase();

}

var e1 = new Employee("jitendra");

var e2 = new Employee("Raju");

console.log(e1.getName()); //JITENDRA

console.log(e2.getName()); //RAJU

}

getEmployeeDetails();

//Overriding alert

var alert = function(msg){

console.log(msg);

}

alert("hello jit");

//Inheritance in javascript

var Employee = function(name){

this.name = name;

}

Employee.prototype.getName = function() {

return this.name;

}

Employee.prototype.getNameLength = function() {

return this.name.length;

}

var PermanentEmployee = function(annualSalary){

this.annualSalary = annualSalary;

}

var employee = new Employee("Jitendra");

PermanentEmployee.prototype = employee;

var pe = new PermanentEmployee(5000);

console.log(pe.getName()) //Jitendra

console.log(pe.annualSalary); //5000

console.log(pe.getNameLength()); //8

console.log(pe instanceof Employee); //true

console.log(pe instanceof PermanentEmployee); //true

console.log("employee.name" + employee.hasOwnProperty('name')); //true

console.log(employee.hasOwnProperty('annualSalary')); //false

//Abstract Class in Javascript

var Shape = function(){

this.ShapeName="none";

throw new Error("Can not create a instance of an abstarct class !!");

}

Shape.prototype.draw = function() {

return "Drawing " + this.ShapeName;

}

var Circle = function(shapeName){

this.ShapeName = shapeName;

}

Circle.prototype= Object.create(Shape.prototype);

var circle = new Circle("Shape1");

console.log(circle.draw()); //Drawing Shape1

//Plymorphism in javscript

var Shape = function (){}

Shape.prototype.draw = function(){

return "I am a generic shape";

}

var Circle = function(){}

Circle.prototype = Object.create(Shape.prototype);

Circle.prototype.draw = function(){

return "I am a circle";

}

var Square = function(){}

Square.prototype = Object.create(Shape.prototype);

Square.prototype.draw = function(){

return "I am a Square";

}

var Traingle = function(){}

Traingle.prototype = Object.create(Shape.prototype);

Traingle.prototype.TraingleName = function (name){

return name;

}

var shapes = [new Shape(), new Circle() , new Square(), new Traingle()];

shapes.forEach(function (shape){

console.log(shape.draw());

});

//Output

//I am a generic shape

//I am a circle

//I am a Square

//I am a generic shape