C# week5_1

22/02/2010

Object oriented Program

• Object: an instance of a class
  
• Class: template that define the form of an object. It specifies both the data and the code that will be operate on the data.
  
  • Member variables: the valuables declared inside a class
    
  • Method: blocks of code that perform some kind of action or functions
    
    • Instance Method
      
    • Static Method
      
• Constructor: using for initializing the member of a class. (default value 0 or NULL or false)
  

  *no return data type
  

ex.

class student

{

int studentID;

string studentname;

int studentage;

}

 
 

student s1, s2;

s1 = new student();

s1.studentID=10;

s2 = new student();

Console.WriteLine(s2.studentID);

 
 

result 0

 
 

ex.

student()

{

studentID = 10;

studentname = "ABC";

}

student s1, s2;

s1 = new student();

s2 = new student();

 
 

result s1 and s2: ID 10 name ABC

 
 

ex.

student()

{

Console.WriteLine("Hello");

}

student s1, s2;

s1 = new student();

 
 

result s1 ID 0 name NULL

 
 

Access specifiers

1. private
   
2. public
   
3. protected
   
4. internal
   
5. protected internal
   

 
 

ex.

class one

{

int i;

int xyz()

{

return 10;

}

}

class two

{

public static void Main

{

one o =new one();

Console.WriteLine(o.i);

}

}

 
 

result 0

 
 

default: private