static variable(static data member) in C++

 //static data member   static variable(static data member) in C++
#include<iostream>
using namespace std;
class Employee
{
    int Id;
    static int count;
    public:
        void setData(void)
        {
            cout<<"Enter the Id"<<endl;;    
        cin>>Id;
        count++;
        }
        void getData(void)
        {
        
  cout<<"This Id of this employee is "<<Id<<"and this employee number "<<count<<endl;
}
};
int Employee :: count;//default vaalueis 0
int main()
{
    Employee harry, rohan ,lovish;
    harry.setData();    
    harry.getData();    
rohan.setData();    
rohan.getData();    
    lovish.setData();    
    lovish.getData();    
    return 0;
}

 output----