C++ examples for Class:Destructor
Defining a destructor and the copy constructor
#include <iostream> #include <string> class Message{/*www.jav a 2 s.c o m*/ private: std::string* ptext; // Pointer to string public: void show() const{ std::cout << "Message is: " << *ptext << std::endl; } // Constructor Message(const char* text = "No message") { ptext = new std::string {text}; // Allocate space for text } // Copy Constructor Message(const Message& message) { ptext = new std::string(*message.ptext); // Duplicate the object in the heap } // Assignment operator Message& operator=(const Message& message) { if (this != &message) ptext = new std::string(*message.ptext); // Duplicate the object in the heap return *this; // Return the left operand } // Destructor ~Message() { delete ptext; } }; // Ouput a copy of a Message object void print(Message message) { message.show(); } int main() { Message beware {"Careful"}; Message warning; warning = beware; // Call assignment operator std::cout << "After assignment beware is:\n"; beware.show(); std::cout << "After assignment warning is:\n"; warning.show(); }