What is the Java Virtual Machine (JVM)?

The JVM is a runtime environment that executes Java bytecode and provides platform independence, memory management, and garbage collection for Java applications.

What is the difference between JDK and JRE?

The JDK includes tools for developing Java applications, while the JRE provides the runtime environment required to execute Java programs.

What are Java collections?

Java collections are data structures from the java.util package, such as List, Set, and Map, that provide methods for storing, accessing, and manipulating groups of objects.

Java Interview Questions

21. What is autoboxing and unboxing?

22. What are classes and objects in Java?

23. What is encapsulation?

24. What is inheritance in Java?

25. What is polymorphism?

26. What is abstraction in Java?

27. What is the difference between abstract classes and interfaces?

28. What are default and static methods in interfaces?

29. What are constructors in Java?

30. What is constructor overloading?