Free Udemy Course 2025: Java Packages & Access Modifiers - Free Udemy Course [100% Off]

Mastering Java Packages and Access Modifiers is a critical milestone for any developer aiming to write clean, secure, and maintainable code. Whether you are preparing for a technical interview or a Java certification, understanding how to encapsulate data and organize classes is essential.Welcome to the most comprehensive practice exams designed to help you prepare for your Java Packages & Access Modifiers - Practice Questions 2026.Why Serious Learners Choose These Practice ExamsThese practice tests are engineered to go beyond rote memorization. We focus on deep conceptual understanding, ensuring you can apply Java’s visibility rules in complex, multi-package environments.You can retake the exams as many times as you want: Perfect your score at your own pace.Huge original question bank: Questions are curated to reflect modern Java standards.Instructor Support: Get direct help if you find a specific concept challenging.Detailed Explanations: Every question includes a breakdown of why an answer is right and why others are wrong.Mobile-Compatible: Study on the go using the Udemy app.30-Day Money-Back Guarantee: A risk-free investment in your career.Course StructureOur curriculum is organized into six logical levels to ensure a smooth learning curve:Basics / Foundations: Focuses on the syntax of declaring packages and the basic purpose of the import keyword. You will learn how the file system relates to package naming.Core Concepts: Deep dives into the four access levels: private, default (package-private), protected, and public. This section reinforces the visibility rules within the same class and same package.Intermediate Concepts: Challenges your knowledge of subclassing across different packages. This is where the nuances of the protected modifier and inheritance are tested.Advanced Concepts: Covers edge cases such as static imports, name shadowing, and the impact of access modifiers on top-level vs. nested classes.Real-world Scenarios: Practical coding problems where you must decide the best access level for API design, focusing on the principle of least privilege.Mixed Revision / Final Test: A comprehensive simulation of a real exam environment, combining all the topics above to test your exam readiness.Sample Practice QuestionsQuestion 1Class A is in package p1 and Class B is in package p2. Class B extends Class A. Class A has a member variable defined as protected int data = 10;. Which statement is true regarding accessing data in Class B?Option 1: Class B can access data only via an instance of Class A.Option 2: Class B can access data directly or via super because it is a subclass.Option 3: Class B cannot access data because it is in a different package.Option 4: Class B can access data only if it is declared public in Class A.Option 5: Class B can access data only using reflection.Correct Answer: Option 2Correct Answer Explanation: The protected modifier allows access to subclasses even if they are in different packages. Since Class B is a subclass of Class A, it inherits the protected members and can access them directly.Wrong Answers Explanation:Option 1: Incorrect. In a different package, a subclass cannot access a protected member through a reference of the parent class; it must be through inheritance.Option 3: Incorrect. protected specifically allows for cross-package access via inheritance.Option 4: Incorrect. While public would work, protected is sufficient for a subclass.Option 5: Incorrect. Reflection is a workaround for private members, but not necessary here.Question 2What happens if you do not specify an access modifier for a class member in Java?Option 1: It defaults to private.Option 2: It defaults to protected.Option 3: It defaults to public.Option 4: It results in a compilation error.Option 5: It defaults to "package-private" (default).Correct Answer: Option 5Correct Answer Explanation: In Java, if no modifier is explicitly stated, the member has "default" access, also known as package-private. This means the member is visible only to other classes within the same package.Wrong Answers Explanation:Option 1: Incorrect. private must be explicitly declared to restrict access to the same class.Option 2: Incorrect. protected must be explicitly declared.Option 3: Incorrect. Java does not default to public for class members to encourage encapsulation.Option 4: Incorrect. Omitting a modifier is valid syntax in Java.Question 3Which of the following modifiers is not allowed for a top-level (non-nested) class?Option 1: publicOption 2: privateOption 3: finalOption 4: abstractOption 5: No modifier (default)Correct Answer: Option 2Correct Answer Explanation: Top-level classes can only be public or have "default" (no modifier) access. They cannot be marked as private or protected.Wrong Answers Explanation:Option 1: Incorrect. public is the most common modifier for top-level classes.Option 3: Incorrect. A class can be final to prevent inheritance.Option 4: Incorrect. A class can be abstract if it is not meant to be instantiated.Option 5: Incorrect. "Default" access is perfectly valid for top-level classes.We hope that by now you're convinced! There are hundreds of additional questions inside the course to ensure you leave no stone unturned in your Java journey.