Java Abstract Class Basics Online Practice Test 1

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Total Questions: 20

Total Minutes: 20

This ExamTray Free Online Test or Quiz or Trivia tests your Programming Skills on the basics of Java Abstract Class. This test displays answers after finishing the exam for review. You can easily clear Competitive Exams and Job Interview Questions. Students can learn Java basics.

Go through Java Theory Notes on Abstract Class before attempting this test.

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1) An abstract class in Java can be created using the keyword ____.

A) final

B) interface

C) abstract

D) static

2) To create an Abstract class, the keyword "class" is also required. State TRUE or FALSE.

A) TRUE

B) FALSE

C) -

D) -

3) Can you create an object from an abstract class in Java?

A) Yes

B) No

C) -

D) -

4) Which is the opposite of an Abstract Class?

A) Interface

B) concrete class

C) -

D) -

5) Choose a correct implementation of an Abstract class in the below Java code?

abstract class ClassA { }

abstract class ClassB
{
  abstract void method();
}

abstract class ClassC
{
  void method()
  {
    System.out.print("Hello Abstract Class");
  }
}

D) All the above

6) An abstract class in Java usually contains one or more abstract ____.

A) constructors

B) methods

C) variables

D) None

7) Does the below Java code with abstract method compile?

class Puppy
{
  abstract void showName();
}

A) NO

B) YES

C) -

D) -

8) What is the output of the below Java program with an abstract class?

abstract class Coffee
{
  Coffee()
  {
    System.out.println("Inside Constructor of Coffee..");
  }
}
class ColdCoffee extends Coffee
{
  ColdCoffee()
  {
    System.out.println("Inside Constructor of ColdCoffee..");
  }
}
public class AbstractClassTesting
{
  public static void main(String[] args)
  {
    ColdCoffee cf = new ColdCoffee();
  }
}

A) Compiler error

Inside Constructor of Coffee..
Inside Constructor of ColdCoffee..

Inside Constructor of ColdCoffee..

Inside Constructor of Coffee..

9) What is the output of the below Java program with an abstract class?

final abstract class Bell
{  }
class DoorBell extends Bell
{
  DoorBell()
  {
    System.out.println("DoorBell ringing..");
  }
}
public class AbstractClassTesting2
{
  public static void main(String[] args)
  {
    Bell bell = new DoorBell();
  }
}

A) DoorBell ringing..

B) No output

C) Compiler error

D) None of the above

10) What is the output of the below Java program with an abstract class?

abstract class MathLibrary
{
  static final float PI = 3.1415f;
}

public class AbstractClassTesting3
{
  public static void main(String[] args)
  {
    System.out.println(MathLibrary.PI);
  }
}

A) No output

B) Compiler error

C) 3.1415

D) None of the above

11) What is the output of the below Java program with multiple abstract classes?

abstract class Editor
{
  abstract void show();
}

abstract class Author extends Editor
{
  abstract void print();
}

class Office extends Author
{
  void show()
  {
    System.out.println("Editor method");
  }
  void print()
  {
    System.out.println("Author method");
  }
}

public class AbstractClassTesting4
{
  public static void main(String[] args)
  {
    Editor ed = new Office();
    ed.show();

    Author au = new Office();
    au.print();	
  }
}

Editor method
Editor method

Author method
Author method

Editor method
Author method

D) Compiler error

12) An object of multi-level inherited abstract class can not be created in memory? State TRUE or FALSE.

A) TRUE

B) FALSE

C) -

D) -

13) An abstract class with 100% abstract methods is equivalent to ______.

A) Concrete class

B) Virtual Class

C) Interface

D) All the above

14) What is the output of the below Java program with an abstract class?

public abstract class AbstractClassTest5
{
  public static void main(String[] args)
  {
    System.out.println("Inside Main() method..");
  }
}

A) No output

B) Compiler error

C) Inside Main() method..

D) None of the above

15) What is the output of the below Java code with an abstract class and inner class?

public abstract class AbstractClassTest6
{
  class Anonymous
  {
    int a=5;
  }
  public static void main(String args[])
  {
    System.out.print("Inner class is present..");	
  }	
}

A) Compiler error

B) Inner class is present..

C) No output

D) None of the above

16) Choose a correct statement about abstract classes?

A) An abstract class can extend a concrete class

B) An abstract class can extend another abstract class

C) An abstract class can implement any number of interfaces.

D) All the above.

17) Choose correct statements about an Abstract class in Java?

A) An abstract class implementing an Interface, need not implement methods of an interface

B) An abstract class extending another abstract class, need not define methods of the super abstract class.