Question about class

Code:

---

#include <iostream>

using namespace std;

class person
{
  private:
  string name;
  int age;

  public:
  person(const string &getname):
              name(getname), age(0){ }

  void addAge(const string &getname)
  {
      age++;
  }

  void getAge(void)
  {
      cout << endl;
      cout << name << " now " << age << " years old";
  }

};


int main()
{
  person *p;
  p = new person("John");
  p->addAge("John");
  p->addAge("John");
  p->addAge("John");
  p->getAge(); //3

  p = new person("Connor");
  p->addAge("Connor");
  p->getAge(); //1

  *p = person("John");
  p->addAge("John");
  p->getAge();      //John age start at 1 again????

  cout << endl;

  return 0;
}

---

How do I increase John age, after I insert new person???
can anyone help me please.
Thank You

What do you mean? When you overwrite Connor with another person called John, the age of the John person is zero. What else did you expect?

Just because you are not doing "new", doesn't mean that the object isn't being created from scratch. The operator new simply gives you some memory to store the object. Regardless of how the memory for the object is created, the constructor is called, which sets age to zero.

--
Mats

Quote:

---

Originally Posted by matsp

What do you mean? When you overwrite Connor with another person called John, the age of the John person is zero. What else did you expect?

Just because you are not doing "new", doesn't mean that the object isn't being created from scratch. The operator new simply gives you some memory to store the object. Regardless of how the memory for the object is created, the constructor is called, which sets age to zero.

--
Mats

---

Hi, thanks for the reply.
So are they any way to go back to my John class to increase his age??

C++ != Java

When you allocate something with the new keyword, you need to delete it.

The person object represents one person. For this reason it is unclear, why you need the name argument to increment the age of a person (the argument is unused in the method). If you want more persons, you'd create more instances (and put them in a container or array, for example).

Besides, when you make p point to another instance allocated with new, you are leaking the object that p pointed to earlier. It still exists in memory but there are no means to get at it.