Object oriented programming With C# C# - Programming - Object Orianted - .Net Programming

1. Object-Oriented Programming
Youssef Mohammed Abohaty
Vice Head Technical at Microsoft Tech Club

2. Agenda : -
• Introduction To OOP .
• Classes .
• Enumeration .
• Structures .
• Encapsulation .
• Inheritance .
• Polymorphism .

3. Introduction To OOP

4. Traditional Programming = Spaghetti code

5. !OOP Programming (OOP Arch Code)
Name Space
Class
Method
Code

6. Why OOP ?
• More Organized Code .
• Debug Fast .
• Fast to Find Errors .
• More Flexible To use .

7. Classes : -
• It’s A container to A Collection of Methods .
• It’s Reference Type .
• Constructors “is a Method With The Same Name Of
The Class” .
• Destructors “is a Method With The Same Name Of The
Class With ~ Before the Name”.
Ex :
Class Persone
{
Public Persone()
{
//Code
}
~ Persone()
{
//Code
}
}

8. Static And Non Static Class
• Non Static Class To Us It Must Make Instance .
Ex :
Person p = new Person();
p.Speak();
• Static Class You Can Us It Direct .
Ex :
Console.WriteLine(“Hello MVA”);
• How To Make A static Class .
Ex :
Static Class Person
{
Private Void Speak()
{
}
}

9. OverLoading : -
• Over Loading Is A Group Of Methods Have The
Same Name !
Ex :
Public Void Speak (int Num);
Public Void Speak (int Num ,String Txt);
Ex :
MessageBox.Show(String Text);
MessageBox.Show(String Text,String Caption);
MessageBox.Show(String Text , String Caption , Message BoxButtons Button);

10. Access Modifier : -
• Public : “ Calling From Any Place “ .
• Private : “ Only Calling From The Same Class “ .
• Protected : “ Only Calling From The Inherit Class “ .
• Internal : “ Only Calling From The Current
Assembly File Only “ .
• Protected Intenal : “ Can Calling From The Inherit
Class And From The Current Assembly File “ .

11. Enumeration : -
• It’s a Group Of Element’s To Represent Cases and
Different Values Inside The Program .
EX :
enum Human
{
Male=0;
Female=1;
}
• Using Name Of enum Only But Real Value stored
as a byte So We Can Use It at (Windows API) .

12. Structures : -
• Is a special Types To Upload any Properties and
Behaviors as variables Or Methods .
Stuct Human
{
Public String JobTitle;
Public int Age;
Public int Year;
};
Human Mahmoud =new Human();
Mahmoud.JobTitle=“Developer”;
Mahmoud.Age=22;
Mahmoud.Year=2015;
• Struct Can Have an Item Is Another Struct .
• Struct Is a Value Type .

13. Encapsulation : -
• Is Hide Our Code And Use It As a Black Box From
The Final Method .
• using Access Modifier .
EX :
Human Ahmed =new Ahmed();
Ahmed.Age=6723896349;
• We Can Use Get(Accessor) And Set (Mutator).
EX :
Person
{
Private int Age;
Public Get Age (int age)
{
If(age <=100 $$ age>=1)
{
Age=age; }
else{console.WriteLine(“We Can’t store This Age”);} }
}

14. Encapsulation (Type Property) : -
Class Person
{
Public int Age
{
get{return Age ; }
set{if (Age<=100 $$ Age>1)
Age=Value;}
}
}

15. Inheritance : -
• What Is Inheritance Mean ?! .
• Is-a Relation .
• Has-a Relation .
• When I can Use Inheritance ?! .
• Multi Inheritance ! .
EX :
Class Developer : Human
{
// Implementation
}

16. Inheritance (Saled“Not Inheritable”) : -
Saled Class Human
{
}
This Way Is Wrong !
Class Teacher : Human ×
{}
• You Can Only Use From Object’s .
• Human Teacher =new Human();

17. Abstract Classes (MustInherit) :-
• Is A class Must Inherit To Use his attributes From
The Inherited Class .
EX :
abstract class Human
{
Public int Age;
}
EX :
class Doctor :Hman
{
}

18. Interface : -
• Is abstract Class With Out Any Implementation .
Interface Human
{
int Age ;
String JobTitle;
int Year;
}
• More Than Once Inherit .

19. Polymorphism : -
• You Can Create Class With Out Any
Implementation .
• You Can Change Methods Implementation by
Overriding between two Different Classes.
Public Virtual void Speak()
{
Console,Beep();
}
Public Override void Speak()
{
Console.WriteLine(“Speak”);
}

20. Abstract Methods : -
• Is a Kind Of Polymorphism but abstract Key Word
Forcing The Developer To Make Override .
Public abstract void Speak()
{
Console,Beep();
}
Public Override void Speak()
{
Console.WriteLine(“Speak”);
}

21. Thank You !
jozeif_abdelkader70@yahoo.com
jozeif_abdelkader70@outlook.com
en9.youssef@gmail.com
twitter.com/Dev_Youssef