In the context of the Singleton pattern, what kind of access point is typically provided?

In the context of the Singleton pattern, what kind of access point is typically provided?

• A. A global access point to the sole instance
• B. A private method for internal use only
• C. A static method that creates new instances
• D. A public constructor for external instantiation

Answer: (A)

In the Singleton pattern, the goal is to provide a single, globally accessible instance of a class. The access point is a global entry point that clients use to obtain that one instance, typically implemented as a static method (for example, getInstance) that returns the same stored instance each time. This design hides the constructor (often making it private) so external code cannot create new objects, ensuring only one instance exists and is shared across the application. The other options don’t fit because a private method would be hidden from external code, a static method that creates new instances would allow multiple instances, and a public constructor would let external code instantiate more than one object, breaking the singleton guarantee.

In the Singleton pattern, the goal is to provide a single, globally accessible instance of a class. The access point is a global entry point that clients use to obtain that one instance, typically implemented as a static method (for example, getInstance) that returns the same stored instance each time. This design hides the constructor (often making it private) so external code cannot create new objects, ensuring only one instance exists and is shared across the application.

The other options don’t fit because a private method would be hidden from external code, a static method that creates new instances would allow multiple instances, and a public constructor would let external code instantiate more than one object, breaking the singleton guarantee.