Singleton Design Pattern is a part of Creational Pattern
Intent
- We have to ensure the class has only one instance, and provide a global point of access to it.
- Encapsulated “just-in-time initialization” or “initialization on first use”.
To be considered for Singleton Design Pattern
- Define a private static attribute in the “single instance” class.
- Define a public static accessor function in the class.
- Do “lazy initialization” (creation on first use) in the accessor function.
- Define all constructors to be protected or private.
- Clients may only use the accessor function to manipulate the Singleton.
Why to read, you can watch the below videos to understand Singleton Design pattern and its implementations ?