Object-oriented in Chapter 03 C #

1. static and dynamic attributes in philosophy correspond to attributes and behaviors respectively.

2. Static methods are accessed by class names. Static methods can only access static members. Non-static methods can access all members.

3. Use of attributes and indexer.

4. Access type modifiers: Public, private, protected, and internal.

5. Static members can be used before the object is created.

Example:

 Using System;

 Public   Class CD
{
Public   String Name;
 Public   Double Price;
 Public   String Type;
 Public CD ( String Name, Double Price, String Type)
{ This . Name = Name; This . Price = price;This . Type = type ;}

}
 Public   Class Videoshop
{
 Private CD [] cdset = New CD [ 10000 ];
 Private   Int Cdcount = 0 ;
 Public   Int Count {Get { Return   This . Cdcount ;}}
 //  1. The first index type  
      Public CD This [ String Cdname]
{
 Get 
{
 Foreach (CD item In Cdset)
If (Item. Name = cdname)
 Return Item;
 Return   Null ;
}
}
 //  2. The second index type  
      Public CD This [ String Cdname, String Type]
{
Get  
{
 Foreach (CD item In Cdset)
 If (Item. Name = cdname & item. type = type)
 Return Item;
 Return   Null ;
}
}
 //  3. The third index type  
      Public CDThis [ Int N]
{
 Set 
{
 If (Cdset [N] = Null ) Cdcount ++;
 If (Value = Null & Cdset [N]! = Null ) Cdcount --;
Cdset [N] = value;
}
 Get 
{
Return Cdset [N];
}
}
}
 Class Test
{
[Stathread]
 Static   Void Main ( String [] ARGs)
{
Videoshop myshop = New Videoshop ();
CD CD1 = New CD ( " Jinling 13-game  " , 45 , "  DVD  " );
CD CD2 = New CD ( "  Rome holiday  " , 25 , "  VCD  " );
Myshop [myshop. Count] = CD1;//  Call index type 3  
 Myshop [myshop. Count] = Cd2; //  Call index type 3  
 Cd a = myshop [ "  Jinling 13-game  " ]; //  Call index type 1  
 Cd B = myshop [ "  Rome holiday  " , "  VCD  " ]; //  Call index type 2  
 Console. writeline ( "  Name: {0} {1}, price: {2}  " , A. type, A. Name, A. Price );
Console. writeline ( "  Name: {0} {1}, price: {2}  " , B. type, B. Name, B. Price );
Console. Readline ();
}
}