base keyword

In this chapter you will learn:

Using base to Access a Hidden Name
Call constructor in base class

Using base keyword

'base' refers to the base class of the derived class in which it is used. This usage has the following general form:

base.member

The following code uses base keyword to access field in the base class.

using System;/*  ja va 2 s  .co m*/

class BaseClass                                      
{
   public string Field1 = "In the base class";
}

class DerivedClass : BaseClass                        
{
   new public string Field1 = "In the derived class";

   public void Display()
   {
      Console.WriteLine("{0}", Field1);              // Access the derived class.
      Console.WriteLine("{0}", base.Field1);         // Access the base class.
   }
}

class Program
{
   static void Main()
   {
      DerivedClass oc = new DerivedClass();
      oc.Display();
   }
}

The code above generates the following result.

Call constructor from base class

The following code shows how to call constructor from base class with base keyword.

using System;/*from jav  a  2  s  .c om*/

public class BaseClass
{
    public BaseClass(int x)
    {
        this.x = x;
    }
    public int X
    {
        get
        {
            return(x);
        }
    }
    int    x;
}

public class Derived: BaseClass
{
    public Derived(int x): base(x)
    {
    }
}

class MainClass
{
    public static void Main()
    {
        Derived d = new Derived(15);
        Console.WriteLine("X = {0}", d.X);
    }
}