singleton class

[ranjitkumar]

What is a singleton class???
What is its use???

[r035198x]

What is a singleton class???
What is its use???

A class whose design is such that it can only be instantiated once. This means only one instance of it can exist e.g Application classes maybe singleton classes

[vermarajeev]

And it could look something like this

class SingleTon
{
public:
	static SingleTon* instance();
private:
	SingleTon(){};
	SingleTon( const SingleTon& );
	SingleTon& operator == ( const SingleTon& );
	static SingleTon* pinstance;
};
SingleTon* SingleTon::pinstance = 0;

SingleTon* SingleTon::instance()
{
	if(pinstance == 0)
	{
		pinstance = new SingleTon;		
	}
	return pinstance;
}

int main(int argc, char** argv[])
{
	
	SingleTon* p1 = SingleTon::instance();
	SingleTon* p2 = p1->instance();
	return 0;
}