Singleton pattern Ensure a class only has one instance, and provide a global point of access to it. This is useful when exactly one object is needed to coordinate actions across the system.
- Singleton pattern is implemented by creating a class with a method that creates a new instance of the object if one does not exist.
- If an instance already exists, it simply returns a reference to that object.
- To make sure that the object cannot be instantiated any other way, the constructor is made either private or protected.