Differentiate between an eager and a lazy Singleton?
The difference between an eager and a lazy Singleton lies in the timing of the instantiation of the Singleton instance:
Eager Singleton:
- In an eager Singleton, the instance of the class is created at the time the class is loaded or the application starts, regardless of whether it will be used immediately or not.
- The instance is created eagerly, and it is readily available for use whenever needed.
- Eager instantiation can help avoid potential concurrency issues in multithreaded environments since the instance is created before any threads start accessing it.
Lazy Singleton:
- In a lazy Singleton, the instance of the class is created only when it is first requested or when it is needed during the program’s execution.
- Lazy instantiation is a form of optimization, as it defers the creation of the instance until it is actually needed, potentially saving resources.
- Lazy instantiation might introduce concurrency concerns, especially in a multithreaded environment, as multiple threads could potentially request the instance simultaneously. To address this, developers often use synchronization mechanisms like locks.
Most asked Singleton Design Pattern Interview Questions
This article comprises some of the most asked Singleton design pattern interview questions, which will help you tackle any Singleton design pattern question properly.