14_4.cpp

ThinkingC++中文版答案 ThinkingC++中文版答案

//14_4

#include <iostream.h>

class CAT{
public:
  CAT();
  CAT(const CAT&);
  ~CAT();
  int GetAge() const { return *itsAge; }
  void SetAge(int age){ *itsAge=age; }
protected:
  int* itsAge;
};

CAT::CAT()
{
  itsAge=new int;
  *itsAge =5;
}

CAT::CAT(const CAT& c)
{
  itsAge = new int;
  *itsAge = *(c.itsAge);
}

CAT::~CAT()
{
  delete itsAge;
  itsAge =0;
}

void main()
{
  CAT frisky;
  cout <<"frisky's age:" <<frisky.GetAge() <<endl;
  cout <<"Setting frisky to 6...\n";
  frisky.SetAge(6);
  cout <<"Creating boots from frisky\n";
  CAT boots(frisky);
  cout <<"frisky's age:" <<frisky.GetAge() <<endl;
  cout <<"boots'age:" <<boots.GetAge() <<endl;
  cout <<"setting frisky to 7...\n";
  frisky.SetAge(7);
  cout <<"frisky's age:" <<frisky.GetAge() <<endl;
  cout <<"boots'age:" <<boots.GetAge() <<endl;
}