Interview Q&A / Object-Oriented Programming

1. How do you make a Singleton thread-safe in Java?

   Use eager initialisation, the holder class idiom, or an enum. If you need lazy creation with double-checked locking, the field must be volatile.

   IntermediateQuick answer1 min read
2. Why do many developers call Singleton an anti-pattern?

   It is global state in disguise: hidden dependencies, hard-to-reset state between tests, tight coupling to one concrete class, and trouble when you later need two instances.

   IntermediateQuick answer1 min read