Mega Code Archive
Pass a derived class reference to a base class reference
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/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Pass a derived class reference to a base class reference.
using System;
class TwoDShape {
double pri_width; // private
double pri_height; // private
// Default constructor.
public TwoDShape() {
width = height = 0.0;
}
// Constructor for TwoDShape.
public TwoDShape(double w, double h) {
width = w;
height = h;
}
// Construct object with equal width and height.
public TwoDShape(double x) {
width = height = x;
}
// Construct object from an object.
public TwoDShape(TwoDShape ob) {
width = ob.width;
height = ob.height;
}
// Properties for width and 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);
}
}
// A derived class of TwoDShape for triangles.
class Triangle : TwoDShape {
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);
}
}
public class Shapes7 {
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());
}
}
]]>