C++ Constructor Copying Instances

 
#include <iostream>
 
using namespace std;
 
class MyClass//from   w  w  w.java  2s.  c  om
{
protected:
    static int myID;
    int newID;
public:
    int SomeNumber;
    int GetID() { return newID; }
    MyClass();
    MyClass(int x);
    MyClass(const MyClass& source);
};
 
MyClass::MyClass()
{
    newID = myID;
    myID++;
}
 
MyClass::MyClass(int x)
{
    newID = myID;
    myID++;
    SomeNumber = x;
}
 
MyClass::MyClass(const MyClass& source)
{
    newID = myID;
    myID++;
    SomeNumber = source.SomeNumber;
}
 
int MyClass::myID;
 
int main()
{
    MyClass take1 = 100;
    MyClass take2;
    take2.SomeNumber = 200;
    MyClass take3 = take1;
 
    cout << take1.GetID() << " "
         << take1.SomeNumber << endl;
    cout << take2.GetID() << " "
         << take2.SomeNumber << endl;
    cout << take3.GetID() << " "
         << take3.SomeNumber << endl;
    return 0;
}