Spring Semester Quiz 6

What will be the output of the following code?

class A {

void display() {

System.out.println("Class A");

}

}

class B extends A {

void display() {

System.out.println("Class B");

}

}

public class Main {

public static void main(String[] args) {

A obj = new B();

obj.display();

}

}

• Class A

• Class B

• Compilation Error

• Runtime Error

Which of the following statements about the Object class in Java is/are FALSE?

• Every Java class extends Object class either directly or indirectly.

• Only classes without a superclass extend Object class.

• The Object class cannot be extended.

• Object class is an abstract class.

The following are not among the primary purposes of encapsulation in Java?

• To restrict access to data and ensure data hiding.

• To group related methods together.

• To implement multiple inheritance.

• To allow direct access to class fields.

Which keyword is used to refer to the immediate parent class in Java?

What happens if an abstract class does not have any abstract methods?

• Java will automatically provide an abstract method.

• It will not compile.

• The class can still be abstract.

• It becomes a concrete class.

What will be the output of this code?

class Animal {

void makeSound() {

System.out.println("Animal makes a sound");

}

}

class Dog extends Animal {

void makeSound() {

System.out.println("Dog barks");

}

}

public class Main {

public static void main(String[] args) {

Animal a = new Dog();

a.makeSound();

}

}

Which of the following statements about abstract classes is/are FALSE?

• 
  Abstract classes cannot have constructors.

• Abstract classes cannot have final methods.

• An object of an abstract class cannot be instantiated.

• Abstract classes cannot have static methods.

The output of the following code is
class Main {

public static void main(String args[]){

final int I;

i = 20;

System.out.println(i);

}

}

Output of the below Java Code is 30?
class Main {

public static void main(String args[]){

final int i;

i = 20;

i = 30;

System.out.println(i);

}

}

• True
• False

try block may or may not contains catch blocks

• True

• False