Pass a derived class reference to a base class reference. : Base Class : Class C# Examples

    
using  System;  
  
class  Shape  {  
    double  pri_width;    //  private  
    double  pri_height;  //  private  
  
    public  Shape()  {  
        width  =  height  =  0.0;  
    }  
  
    public  Shape(double  w,  double  h)  {  
        width  =  w;  
        height  =  h;  
    }  
  
    public  Shape(double  x)  {  
        width  =  height  =  x;  
    }  
  
    public  Shape(Shape  ob)  {  
        width  =  ob.width;  
        height  =  ob.height;  
    }  
  
    public  double  width  {  
          get  {  return  pri_width;  }  
          set  {  pri_width  =  value;  }  
    }  
  
    public  double  height  {  
          get  {  return  pri_height;  }  
          set  {  pri_height  =  value;  }  
    }  
  
    public  void  showDim()  {  
        Console.WriteLine("Width  and  height  are  "  +  
                                              width  +  "  and  "  +  height);  
    }  
}  
  
class  Triangle  :  Shape  {  
    string  style;  //  private  
      
    //  A  default  constructor.  
    public  Triangle()  {  
        style  =  "null";  
    }  
  
    //  Constructor  for  Triangle.  
    public  Triangle(string  s,  double  w,  double  h)  :  base(w,  h)  {  
        style  =  s;    
    }  
  
    //  Construct  an  isosceles  triangle.  
    public  Triangle(double  x)  :  base(x)  {  
        style  =  "isosceles";    
    }  
  
    //  Construct  an  object  from  an  object.  
    public  Triangle(Triangle  ob)  :  base(ob)  {  
        style  =  ob.style;  
    }  
  
    //  Return  area  of  triangle.  
    public  double  area()  {  
        return  width  *  height  /  2;  
    }  
  
    //  Display  a  triangle's  style.  
    public  void  showStyle()  {  
        Console.WriteLine("Triangle  is  "  +  style);  
    }  
}  
  
class  MainClass  {  
    public  static  void  Main()  {  
        Triangle  t1  =  new  Triangle("right",  8.0,  12.0);  
  
        //  make  a  copy  of  t1  
        Triangle  t2  =  new  Triangle(t1);  
  
        Console.WriteLine("Info  for  t1:  ");  
        t1.showStyle();  
        t1.showDim();  
        Console.WriteLine("Area  is  "  +  t1.area());  
  
        Console.WriteLine();  
  
        Console.WriteLine("Info  for  t2:  ");  
        t2.showStyle();  
        t2.showDim();  
        Console.WriteLine("Area  is  "  +  t2.area());  
    }  
}