These are the most common Java Developer interview questions and how to answer them:
JDK (Java Development Kit) is a software development kit used to develop Java applications. JRE (Java Runtime Environment) is a set of software tools for running Java applications. JVM (Java Virtual Machine) is a part of JRE that executes Java bytecode.
JVM is an abstract computing machine that enables a computer to run a Java program. JVM performs all the main tasks such as memory management, garbage collection, and security. It provides a platform-independent way of executing code.
The main principles of object-oriented programming (OOP) in Java are encapsulation, inheritance, polymorphism, and abstraction. Encapsulation hides the internal state and code structure. Inheritance allows the creation of new classes based on existing ones. Polymorphism lets methods do different things based on the object it is acting upon. Abstraction simplifies complex reality by modeling classes appropriate to the problem.
The 'final' keyword in Java can be applied to variables, methods, and classes. A final variable cannot change its value once initialized. A final method cannot be overridden by subclasses. A final class cannot be subclassed.
Exceptions are events that disrupt normal flow of the program. Java uses a try-catch block to handle exceptions. The code that might throw an exception is placed inside the try block, and catch blocks handle specific types of exceptions. A finally block can be used to execute code after try and catch blocks regardless of whether an exception occurs.
ArrayList uses a dynamic array to store elements, providing fast random access but slow insertion and deletion of elements, except at the end. LinkedList uses a doubly-linked list to store elements, providing efficient insertion and deletion even in the middle but slower access.
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