hour12_3a.cpp

C++学习的有利助手

 //Listing 12.1
 // Passing pointers to objects
 // passobjectsbyref.cpp
 #include <iostream>
 
 class SimpleCat
 {
 public:
     SimpleCat ();                    // constructor
     SimpleCat(SimpleCat&);     // copy constructor
     ~SimpleCat();                    // destructor
 };
 
 SimpleCat::SimpleCat()
 {
     std::cout << "Simple Cat Constructor...\n";
 }
 
 SimpleCat::SimpleCat(SimpleCat&)
 {
     std::cout << "Simple Cat Copy Constructor...\n";
 }
 
 SimpleCat::~SimpleCat()
 {
     std::cout << "Simple Cat Destructor...\n";
 }
 
 SimpleCat FunctionOne (SimpleCat theCat);
 SimpleCat* FunctionTwo (SimpleCat *theCat);
 
 int main()
 {
     std::cout << "Making a cat...\n";
     SimpleCat Frisky;
     std::cout << "address of Frisky " << &Frisky << "\n";
     std::cout << "Calling FunctionOne...\n";
     FunctionOne(Frisky);
     std::cout << "Calling FunctionTwo...\n";
     FunctionTwo(&Frisky);
     return 0;
 }
 
 // FunctionOne, passes by value
 SimpleCat FunctionOne(SimpleCat theCat)
 {
     std::cout << "address of Frisky in Function One " << &theCat << "\n";
     std::cout << "Function One. Returning...\n";
     return theCat;
 }
 
 // functionTwo, passes by reference
 SimpleCat* FunctionTwo (SimpleCat  *theCat)
 {
     std::cout << "address of Frisky in Function Two" << theCat << "\n";
     std::cout << "Function Two. Returning...\n";
     return theCat;
 }