Frist Class In OOP 

Just open your c++ compiler Paste this code.

#include <iostream>
using namespace std;
class smallobj
{
private:
int somedata;
public:
void setdata(int d)
{
 somedata = d;
 cout << "Data is "<< d << endl;
}
};
int main()
{
smallobj s1;
s1.setdata(10);
}