'Singleton' Design Pattern using simple program

Definition: Ensure a class only has one instance and provide a global point of access to it.

Program:

#include "iostream"
using namespace std;

class Singleton
{
private:
    static Singleton* instance;
    Singleton() {}

public:
    static Singleton* Instance()
    {
        if(instance == NULL)
        {
            instance = new Singleton();
        }
        return instance;
    }

    void Show()
    {
        cout<<"Singleton Class"<<endl;
    }
};

Singleton* Singleton::instance = NULL;

int main()
{
    Singleton* obj1 = Singleton::Instance();
    obj1->Show();

    Singleton* obj2 = Singleton::Instance();
    obj2->Show();

    getchar();

    return 0;
}

/*
OUT PUT
-------
Singleton Class
Singleton Class
*/