C++ Programming - OOPS Concepts - Discussion

A class whose number of instances that can be instantiated is limited to one is called a singleton class. Thus, at any given time only one instance can exist, no more.

The singleton design pattern is used whenever the design requires only one instance of a class. Some examples:.

Application classes. There should only be one application class. (Note: Please bear in mind, MFC class 'CWinApp' is not implemented as a singleton class).

Logger classes. For logging purposes of an application there is usually one logger instance required.

I can't understand properly concept of Singleton class. ?

I can't get your definition. Can you make me understand easier?

Tell me also what is singleton class?

Write the use of singleton class in a program in easy to understand language.

How to make singleton class?

A class whose number of instances that can be instantiated is limited to one is called a singleton class. Thus, at any given time only one instance can exist, no more.

Write a simple exemples in Singleton class?

class A
{
private:
static A* m_objA;
A(){}; //note constructor is private
public:
~A();
A* GetInstance()
{
if(m_objA)
{
return m_objA;
}
else
{
m_objA = new A();
return m_objA;
}
}
};

What is the use of singleton class?