Java Programming – 60+ Exam Q&A on Inheritance, Interfaces, Polymorphism – CS101

This document includes 60+ fully solved and clearly structured exam-style questions and answers covering essential Object-Oriented Programming (OOP) topics for the Intro to Java Programming (CS101) course, aligned with the 2025/2026 academic year. It is designed for first-year Computer Science, Software Engineering, and IT students, and is highly valuable for mastering core Java OOP concepts ahead of exams, quizzes, or interviews. All questions are written in a terminology + definition format and focus on clear conceptual understanding. Verified answers follow each question immediately, ensuring maximum clarity and fast-paced study. This document is ideal for flashcard use, class revision, or concept reinforcement. Main topics covered: Inheritance: extending classes, use of super, field and method inheritance, upcasting Interfaces and Abstract Classes: implements vs extends, abstract methods, default methods (Java 8), instantiation rules Access Control & Visibility: public, private, protected, package-private, visibility across packages and subclasses Encapsulation & Abstraction: method/field hiding, exposing behavior, restricting access to internal state Polymorphism: dynamic method dispatch, type handling, instanceof, treating objects as base types Overloading vs Overriding: method signature differences, compile-time vs runtime behavior Object Class Methods: .equals(), .toString(), .hashCode() Memory & References: variable memory addresses, null references, default constructors Encapsulation & State Management: using private fields, constructors, and setters Shadowing & Scope: variable shadowing, local vs global visibility Static Context: static methods, static-only interactions, access limits Class Structure: fields, methods, and constructors with parameters This content is well-suited for: CS101 students preparing for object-oriented programming sections Java beginners learning OOP terminology and usage rules Certification candidates (e.g., Oracle OCAJP) reinforcing Java theory Tutors developing flashcard sets or quizzes based on OOP fundamentals The concise question-answer format and focus on conceptual correctness make this an excellent OOP-focused study guide and exam prep resource. Keywords: Java inheritance, Java interfaces, Java polymorphism, Java encapsulation, Java abstraction, method overriding, method overloading, Java access modifiers, Java abstract classes, instanceof Java, Java object reference, Java shadowing, static methods, CS101 Java, Java exam prep