C++ examples for Class:Inheritance
Using a derived class copy constructor
#include <iostream> #include <string> // For the string class #include <iomanip> class Pool/*from w ww .ja va 2s .c om*/ { protected: double length {1.0}; double width {1.0}; double height {1.0}; public: // Constructors Pool(double lv, double wv, double hv) : length {lv}, width {wv}, height {hv} { std::cout << "Pool(double, double, double) called.\n"; } Pool(double side) : Pool {side, side, side} { std::cout << "Pool(double) called.\n"; } Pool() { std::cout << "Pool() called.\n"; } // No-arg constructor // Copy constructor Pool(const Pool& pool) : length {pool.length}, width {pool.width}, height {pool.height} { std::cout << "Pool copy constructor" << std::endl; } double volume() const // Function to calculate the volume { return length*width*height; } // Accessors double getLength() const { return length; } double getWidth() const { return width; } double getHeight() const { return height; } friend std::ostream& operator<<(std::ostream& stream, const Pool& pool); }; // Stream output for Pool objects inline std::ostream& operator<<(std::ostream& stream, const Pool& pool) { stream << " Pool(" << std::setw(2) << pool.length << "," << std::setw(2) << pool.width << "," << std::setw(2) << pool.height << ")"; return stream; } using std::string; class Carton : public Pool { private: string material {"Cardboard"}; public: Carton(double lv, double wv, double hv, const string desc) : Pool {lv, wv, hv}, material {desc} { std::cout << "Carton(double,double,double,string) called.\n"; } Carton(const string desc) : material {desc} { std::cout << "Carton(string) called.\n"; } Carton(double side, const string desc) : Pool {side}, material {desc} { std::cout << "Carton(double,string) called.\n"; } Carton() { std::cout << "Carton() called.\n"; } // Copy constructor Carton(const Carton& carton) : /*Pool {carton}, */ material {carton.material} // Uncomment for correct operation { std::cout << "Carton copy constructor" << std::endl; } }; int main() { // Declare and initialize a Carton object Carton carton(20.0, 30.0, 40.0, "Glassine board"); Carton cartonCopy(carton); // Use copy constructor std::cout << "Volume of carton is " << carton.volume() << std::endl << "Volume of cartonCopy is " << cartonCopy.volume() << std::endl; }