*Java interview questions along with brief answers* *1. What is the difference between == and .equals() in Java?* == compares object references, while .equals() compares the content of objects. *2. Explain the difference between ArrayList and LinkedList.* ArrayList uses a dynamic array to store elements, providing fast random access. LinkedList uses a doubly-linked list, offering efficient insertion and deletion. *3. What is the significance of the static keyword in Java?* The static keyword is used to create variables and methods that belong to the class rather than instances of the class. These can be accessed without creating an object. *4. What is the difference between an abstract class and an interface?* An abstract class can have both abstract (unimplemented) and concrete (implemented) methods, while an interface can only have abstract methods. A class can implement multiple interfaces, but it can extend only one abstract class. *5. What is the purpose of the finally block in exception handling?* The finally block is used to ensure that a specific block of code is always executed, regardless of whether an exception is thrown or not. *6. Explain the concept of multithreading in Java.* Multithreading is the concurrent execution of two or more threads. Threads allow programs to run tasks in parallel, improving performance. In Java, you can create threads by extending the Thread class or implementing the Runnable interface. *7. What is the NullPointerException and how can it be avoided?* NullPointerException occurs when you try to access a method or field of an object that is null. To avoid it, ensure that objects are properly initialized before accessing their members. *8. How does garbage collection work in Java?* Garbage collection is the process of automatically reclaiming memory occupied by unreferenced objects. Java uses a garbage collector to identify and delete objects that are no longer reachable. *9. Explain the final keyword in Java.* The final keyword can be applied to variables, methods, and classes. When applied to a variable, it means the variable's value cannot be changed. When applied to a method, it prevents method overriding. When applied to a class, it prevents the class from being subclassed. *10. What is the Java Virtual Machine (JVM)?* JVM is a virtual machine that executes Java bytecode. It abstracts the hardware and operating system details, allowing Java programs to run on any device with a compatible JVM. These questions cover a range of Java concepts commonly discussed in interviews. Be prepared to elaborate on your answers and provide examples if requested during an interview. *React ❤️ for more*