Inheritance in Java Quiz

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

What is the purpose of the dispContact() method in the Person class?

  • To set the contact information of a `Person` object
  • To get the contact information of a `Person` object
  • To print the contact information of a `Person` object (correct)
  • To delete the contact information of a `Person` object

Which of the following is a correct statement about the visibility of class members in Java inheritance?

  • Public class members are not accessible by subclasses
  • Private class members are accessible by subclasses
  • Protected class members are accessible by subclasses (correct)
  • Default class members are accessible by subclasses

What is the relationship between the Person, Employee, and Customer classes in the given code?

  • The `Employee` and `Customer` classes inherit from the `Person` class (correct)
  • The `Person` class inherits from the `Employee` and `Customer` classes
  • The `Employee` and `Customer` classes are independent of the `Person` class
  • The `Employee` class inherits from the `Customer` class, and both inherit from the `Person` class

What is the purpose of the empID and designation fields in the Employee class?

<p>To store the employee's identification and job title (B)</p> Signup and view all the answers

What is the purpose of the customerID and invoiceNo fields in the Customer class?

<p>To store the customer's identification and invoice number (A)</p> Signup and view all the answers

What is the significance of the statement 'OOP Java is the easiest, scoring and my favorite subject' in the given text?

<p>It is a statement made by a student about their experience with Java programming (A)</p> Signup and view all the answers

What does polymorphism refer to in object-oriented programming?

<p>The ability of an object to take on many forms (B)</p> Signup and view all the answers

Which access modifier allows a class to be accessed from anywhere?

<p>Public (A)</p> Signup and view all the answers

Why is multiple and hybrid inheritance not supported in Java?

<p>To avoid the Diamond Problem (A)</p> Signup and view all the answers

What is the superclass of every other class in Java?

<p>Object (D)</p> Signup and view all the answers

Can a class extend more than one class in Java?

<p>No, Java does not support multiple inheritance (A)</p> Signup and view all the answers

What does the term 'Polymorphism' mean in object-oriented programming?

<p>The ability of a method to do different things based on the object calling it (C)</p> Signup and view all the answers

What is the purpose of the r variable in the code snippet?

<p>To store a reference of type <code>A</code> (B)</p> Signup and view all the answers

What is the output of the code snippet?

<p>inside class A, inside class B, inside class C (A)</p> Signup and view all the answers

What is the purpose of the if statement in the MyProg class?

<p>To assign the appropriate <code>Game</code> object to the <code>g</code> variable based on user input (C)</p> Signup and view all the answers

What is the purpose of the type() method in the Game class and its subclasses?

<p>To print the type of the game (B)</p> Signup and view all the answers

What is the relationship between the Game class and its subclasses?

<p>The <code>Game</code> class and its subclasses are all concrete classes (A)</p> Signup and view all the answers

What is the purpose of the Scanner object in the MyProg class?

<p>To read user input and store it in the <code>op</code> variable (C)</p> Signup and view all the answers

Which type of polymorphism is achieved through method overloading in Java?

<p>Compile-time Polymorphism (B)</p> Signup and view all the answers

In method overriding, what relationship must exist between the classes containing the overridden method?

<p>IS-A (Inheritance) relationship (B)</p> Signup and view all the answers

What is the main advantage of dynamic method dispatch in Java?

<p>Enables run-time polymorphism (A)</p> Signup and view all the answers

Which type of polymorphism is associated with dynamic method dispatch in Java?

<p>Run-time Polymorphism (A)</p> Signup and view all the answers

How does method overloading differ from method overriding?

<p>Method overloading uses different parameter types or number of parameters; overriding uses the same parameter types. (C)</p> Signup and view all the answers

Why does Java prohibit assigning a parent class object reference to a child class object directly?

<p>To avoid ambiguity in method resolution during dynamic method dispatch. (B)</p> Signup and view all the answers

What is the purpose of the VehicleInterface in the given code?

<p>To define a contract that must be implemented by any class representing a vehicle (A)</p> Signup and view all the answers

What is the significance of the implements keyword in the CarClass declaration?

<p>It forces <code>CarClass</code> to provide implementations for all methods defined in <code>VehicleInterface</code> (A)</p> Signup and view all the answers

What is the purpose of the line VehicleInterface CarClass c = new CarClass(); in the DemoInterface class?

<p>It creates a new instance of <code>CarClass</code> and assigns it to a variable of type <code>VehicleInterface</code> (C)</p> Signup and view all the answers

What is the purpose of the final keyword in the declaration int a = 10; within the VehicleInterface?

<p>It makes the variable <code>a</code> constant and unchangeable (C)</p> Signup and view all the answers

What is the output of the given code?

<p>Left (C)</p> Signup and view all the answers

Which statement is true about methods declared in an interface?

<p>They are implicitly <code>public</code> and <code>abstract</code> (A)</p> Signup and view all the answers

Flashcards are hidden until you start studying

More Like This

Use Quizgecko on...
Browser
Browser