A private variable can be accessed from another object of the same type? [duplicate]

Question

Possible Duplicate:
With a private modifier, why can the member in other objects be accessed directly?

Private members of a C++ class are designed to be invisible to other class instances. I'm confused since private members can be accessed as shown below! Can anyone explain it to me?

Here's my code:

#include <iostream> 
using namespace std; 
class Person
{
private:
    char* name;
    int age;
public:
    Person(char* nameTemp, int ageTemp)
    {
      name = new char[strlen(nameTemp) + 1];
      strcpy(name, nameTemp);
      age = ageTemp;
    }
    ~Person()
    {
      if(name != NULL)
        delete[] name;
      name = NULL;
    }
    bool Compare(Person& p)
    {
      //p can access the private param: p
      //this is where confused me
      if(this->age < p.age) return false;
        return true;
    }
};
int main() 
{ 
  Person p("Hello, world!", 23);
  return 0; 
}

Answer 1

Methods of a class can access its private attributes throughout all class instances, at least in C++.