Your code has a few mistakes... heres how it should look....
Code:
class dog
{
public:
dog() : Age(0) {}
dog(int age) : Age(age) {}
int GetAge() const { return Age;}
void SetAge(const int age) { Age = age;}
private:
int Age;
}
#include <iostream>
using std::cout;
using std::endl;
int main()
{
dog Fred;
dog Joe(10);
cout << Joe.GetAge()<<endl;
Fred.SetAge(15);
cout << Fred.GetAge()<<endl;
Joe = Fred; // uses compiler provided default copy assignment operator.
cout << Joe.GetAge()<<endl;
return 0;
}