OOPS Example

Question

Hello Can anyone give me an C# code example which covers all 4 oops principal. I want all in only one example. -Thanks

Vulpes · Answer

Try this example which illustrates inheritance polymorphism and encapsulation. What did you have in mind for the fourth? using System; class Parent // encapsulation - encapsulates data and method into a class { private string name; // data hiding - hides state from outside code public string Name // property exposes state to outside code { get { return name; } set { name = value; } } public Parent(string name) { this.name = name; } public Parent(){} public void MyMethod() { Console.WriteLine(Hello from Parent.MyMethod); } public virtual void MyVirtMethod() { Console.WriteLine(Hello from Parent.MyVirtMethod); } } class Derived : Parent // inheritance - inherits from Derived { public override void MyVirtMethod() { Console.WriteLine(Hello from Derived.MyVirtMethod); } } class Test { static void Main() { Derived d = new Derived(); d.MyMethod(); // inheritance - MyMethod inherited from Parent Parent p = d; p.MyVirtMethod(); // polymorphism - Derived.MyVirtMethod called because p refers to a Derived object p = new Parent(Fred); Console.WriteLine(p.Name); Console.ReadKey(); } }

Rahul Shah · Answer

Yeah example that you have given is batter that my one...lolz.. BdwNow I finally got all 4 oops principal clearly. Thanks a lot for your help.

Vulpes · Answer

I suppose technically yes though the user could have a good guess at how it's done :) A better example would be a method which returns a random number. Here even an expert user would not how the random number was arrived at because there are various algorithms which can generate pseudo-random numbers. All that matters to the user is that the number is sufficiently random for his/her purposes - the algorithm used is unimportant.

Rahul Shah · Answer

Consider that I am referring one dll in my project. It has one class called Calc having method called Sum().sum funcation will return sum of two numbers. Now I only know that Sum() function will return sum of two numbers.I don;t know how it will do that. Can we Called it an Abstrction ?

Vulpes · Answer

Abstraction is the process of representing some 'real world' object or concept with a software object. The latter tends to be simpler than the former because you generally only need to concentrate on the basic properties and functionality of what you're trying to model and ignore or hide everything else. On the other hand encapsulation means the welding together of data and operations on those data into a single software object. This is in contrast to procedural programming where data and functions which operate on it are essentially separate from each another. Encapsulation provides a mechanism for hiding data or functionality in the form of 'access modifiers' and therefore has a close relationship with abstraction. It's difficult to represent abstraction in the example as it's something which is considered more when designing your classes rather than implementing them. However if you imagine some operation which the class needs to carry out internally and then expose the result (but not how it is achieved) to the user then that's a form of abstraction.

Rahul Shah · Answer

Thanks for giving such a nice example. The forth thing I was talking about is Abstraction. I want to know exact difference between Abstraction and Encapsulation..