Csharp/CSharp Tutorial/Class/public

Public vs private access

It is OK for a member of a class to access a private member of the same class.

<source lang="csharp">using System;

class MyClass {

 private int a; // private access explicitly specified 
 int b;          // private access by default 
 public int gamma;  // public access 
  
 public void setAlpha(int val) { 
   a = val;  
 } 

 public int getAlpha() { 
   return a; 
 } 

 public void setBeta(int a) { 
   b = a;  
 } 

 public int getBeta() { 
   return b; 
 } 

}

class AccessDemo {

 public static void Main() {  
   MyClass ob = new MyClass();  
 
   /* Access to a and b is allowed only through methods. */ 
   ob.setAlpha(-99); 
   ob.setBeta(19); 
   Console.WriteLine("ob.a is " + ob.getAlpha()); 
   Console.WriteLine("ob.b is " + ob.getBeta()); 

   // You cannot access a or b like this: 

// ob.a = 10; // Wrong! a is private! // ob.b = 9; // Wrong! b is private!

   // It is OK to directly access gamma because it is public. 
   ob.gamma = 99;  
  }  

}</source>

ob.a is -99
ob.b is 19

Re-using Base Class Identifiers

<source lang="csharp">class Point2D {

   public int X;
   public int Y;

}

class Point3D : Point2D {

   public int X;
   public int Y;
   public int Z;

}

class MyMainClass {

   public static void Main()
   {
       Point2D My2DPoint = new Point2D();
       Point3D My3DPoint = new Point3D();
  
       My2DPoint.X = 100;
       My2DPoint.Y = 200;
  
       My3DPoint.X = 150;
       My3DPoint.Y = 250;
       My3DPoint.Z = 350;
   }

}</source>

Use an access modifier with an accessor

<source lang="csharp">using System;

class MySequence {

 int prop;   
 
 public MySequence() { prop = 0; }  
 
 public int MyProp {  
   get {  
     return prop;  
   }  
   private set { // private  
     prop = value;  
   }   
 }  

 public void increaseSequence() { 
   MyProp++; 
 } 

}

class MainClass {

 public static void Main() {   
   MySequence ob = new MySequence();  
 
   Console.WriteLine("Original value of ob.MyProp: " + ob.MyProp);  
 
   ob.increaseSequence(); 
   Console.WriteLine("Value of ob.MyProp after increment: " 
                     + ob.MyProp);  
 }  

}</source>

Original value of ob.MyProp: 0
Value of ob.MyProp after increment: 1