hour13_1.cpp

《24学时精通c++》的随书源码的下半部分。欢迎下载学习。

 //Listing 13.1 Overloading class member functions
 #include <iostream>
 
 // Rectangle class declaration
 class Rectangle
 {
 public:
     // constructors
     Rectangle(int width, int height);
     ~Rectangle(){}
 
     // overloaded class function DrawShape
     void DrawShape() const;
     void DrawShape(int aWidth, int aHeight) const;
     void DrawShape(int aWidth=2, int aHeight=3) const;   // Well, this is how you'd create the prototype, but
                                                          // how do you make a different function definition?
                                                          // You will get a compile error because the compiler
                                                          // can't figure out which version to call!  Sorry.
                                                          // This means that the args to overloaded functions
                                                          // must be different in type or number in order to work.
                                                          // In this case they are the same types and number.
 
 private:
     int itsWidth;
     int itsHeight;
 };
 
 //Constructor implementation
 Rectangle::Rectangle(int width, int height)
 {
     itsWidth = width;
     itsHeight = height;
 }
 
 
 // Overloaded DrawShape - takes no values
 // Draws based on current class member values
 void Rectangle::DrawShape() const
 {
     DrawShape( itsWidth, itsHeight);
 }
 
 
 // overloaded DrawShape - takes two values
 // draws shape based on the parameters
 void Rectangle::DrawShape(int width, int height) const
 {
     for (int i = 0; i<height; i++)
     {
         for (int j = 0; j< width; j++)
         {
             std::cout << "*";
         }
         std::cout << "\n";
     }
 }
 
 // Driver program to demonstrate overloaded functions
 int main()
 {
     // initialize a rectangle to 30,5
     Rectangle theRect(30,5);
     std::cout << "DrawShape(): \n";
     theRect.DrawShape();
     std::cout << "\nDrawShape(40,2): \n";
     theRect.DrawShape(40,2);
     return 0;
 }