Java Interview Questions

Welcome to our comprehensive guide on essential Java interview questions! Whether you're a beginner or an experienced developer, this post will help you prepare for your next job interview with key questions, multiple-choice questions (MCQs), and coding challenges.

Key Interview Questions

1. What is Java? Explain its key features.

   • Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. Key features include platform independence, object-oriented, robust, secure, and multithreaded.

2. Explain the concept of Object-Oriented Programming (OOP) and its principles.

   • OOP is a programming paradigm based on the concept of objects, which can contain data and methods. The four main principles of OOP are Encapsulation, Inheritance, Polymorphism, and Abstraction.

3. What is the difference between JDK, JRE, and JVM?

   • JDK (Java Development Kit): A software development environment used for developing Java applications.
   • JRE (Java Runtime Environment): A set of software tools for the development of Java applications.
   • JVM (Java Virtual Machine): An engine that provides a runtime environment to drive the Java Code or applications.

4. What are Java's access modifiers?

   • The access modifiers in Java are public, protected, default, and private. They define the visibility scope of classes, methods, and variables.

5. What is the difference between == and equals() in Java?

   • == compares reference equality (whether both references point to the same object).
   • equals() compares the content equality (whether both objects have the same content).