Java Programming – 80+ Practice Q&A on Greenfoot, Inheritance, Methods, Loops – CS101

This document offers 80+ exam-style Java questions with accurate, direct answers, specifically developed for the Intro to Java Programming (CS101) course using Greenfoot—a visual Java IDE popular in high school and first-year university-level programming. Tailored for the 2025/2026 academic year, it supports foundational understanding of Java syntax, object-oriented programming, and Greenfoot-based logic structures. Structured in a terminology and short-answer format, this resource is ideal for beginner-level students in Computer Science, Software Engineering, or IT, especially those using Greenfoot to explore inheritance, actors, methods, and game logic. The answers are clearly marked and written in an accessible, exam-aligned format. Key topics covered include: Greenfoot Programming Concepts: Actor, World, object placement, method overrides, turning, movement Class and Method Structure: method signatures, return types, parameters, method calling syntax Object-Oriented Design: inheritance, class instantiation, abstract classes (e.g., why Actor cannot be instantiated), use of super() Control Flow & Loops: if statements, while loops, loop conditions, infinite loops, variable counters Random Behavior: use of GRandomNumber(), simulating probabilistic behavior Arrays & Indexing: structure, access with indices, benefits of arrays Access Modifiers: difference between public and private methods String Concatenation: definition and usage in Java Boolean Logic & Comparison Operators: ==, !=, >, <, >=, <=, &&, ||, ! Debugging & Code Comments: comment types (//, /* */), rationale, and documentation use Method Abstraction & Reusability: separating logic into helper methods like lookForWorm() Compiler & Runtime Concepts: JVM, compiler, bytecode, class instantiation Crab & Worm Simulation Logic: sample conditional behaviors such as collision detection, turning, and interaction in Greenfoot This document is especially suitable for: High school AP Computer Science A or IB Computer Science students using Greenfoot University students in CS101 courses with Greenfoot-based labs or assignments Tutors building Java quizzes around visual logic simulation New Java learners needing structured revision on OOP through a visual IDE Self-learners using Greenfoot as a first step into Java programming Its highly practical format mirrors real-world classroom and assignment questions in both Java and Greenfoot contexts, offering a complete, beginner-friendly Java Q&A bank. Keywords: Greenfoot Java, Java inheritance, Greenfoot actor, Java method signature, Greenfoot worm crab, Java random number, Java for loop, Java access modifier, Java arrays, Java comments, Java boolean logic, Java method call, CS101 Java, Java public private, Java object-oriented