Objects and Classes II FiniteQuest

Objects and Classes II

Objects and Classes in Programming, Constructors, Encapsulation and Access Modifiers, Static Members, Inheritance and Polymorphism, Advanced Topics: Anonymous Objects and Inner Classes, Object Cloning, Real-world Object Representation, E-commerce System

1 / 10

Which of the following is true about inheritance?

A subclass can inherit private members of the superclass directly.

A subclass cannot override methods from the superclass.

Inheritance allows a subclass to reuse the fields and methods of a superclass.

A class can inherit from multiple superclasses in Java.

2 / 10

What does method overriding require?

Methods must have different names but the same signature.

Methods must have the same name and signature but be in different classes in the same hierarchy.

Both methods must be static.

Methods must have the same name but different parameters.

3 / 10

What is an anonymous object in Java?

An object without a class.

An object created without assigning it to a reference variable.

An object created using reflection.

None of the above.

4 / 10

Which of the following is true about inner classes?

Inner classes cannot access private members of the outer class.

Static inner classes require an instance of the outer class to be created.

Inner classes can help logically group classes that will only be used within an outer class.

Inner classes are only used for anonymous objects.

5 / 10

What does the clone() method in Java do?

It creates a shallow copy of an object.

It creates a deep copy of an object.

It creates a new object with the same reference as the original.

None of the above.

6 / 10

Which interface must a class implement to support cloning?

Serializable

Cloneable

Clonable

Comparable

7 / 10

A company is designing a library management system. Which of the following best represents the relationship between objects and classes?

Each book is a class, and its details (e.g., title, author) are objects.

A "Book" is a class, and individual books (e.g., "Java Basics", "Python Guide") are objects.

A "Book" is an object, and each instance of the book (e.g., title, author) is a class.

The "Library" is an object, and the "Book" is a method.

8 / 10

In a banking system, a BankAccount class has fields accountNumber, accountHolder, and balance. Which approach ensures that the balance cannot be directly modified by the user, but can be updated via methods?

Use the static modifier for the balance field.

Declare the balance field as protected.

Make the balance field private and provide deposit() and withdraw() methods.

Use the public access modifier for the balance field.

9 / 10

In an e-commerce system, you are creating a Product class with the following requirements:

Each product has a productID, name, and price.
Products should automatically generate a productID when created.
Which approach is the most efficient to handle this?

Use a static variable to keep track of the last used productID and increment it in the constructor.

Assign a random productID in the constructor using the Math.random() method.

Use a final variable for productID and manually assign it to each object.

Use a default constructor to set productID to null.

10 / 10

In a mobile application, a User class has methods login() and logout(). You also need a PremiumUser class with an additional accessPremiumContent() method. Which design principle is best suited for this scenario?

Use method overriding to redefine login() and logout() in PremiumUser.

Use inheritance to create PremiumUser as a subclass of User.

Use an interface to define accessPremiumContent() and implement it in both User and PremiumUser.

Create separate classes for User and PremiumUser without any relationship.

Your score is

By WordPress Quiz plugin