Quiz for Module3

Suppose A is an abstract class, B is a concrete subclass of A. Both A and B have a default constructor.

Which of the following options are correct?

1. A a = new A();

2. A a= new B();

3. B b = new A();

4. B b= new B();

• 1 and 2

• 2 and 4

• 3 and 4

• 1 and 3

Predict the output:

• a=10

• a=20

• Compilation Error at Line 3 : Constructor name should be same as that of class name.

• Compilation Error at

  Line 7 : Method cannot be both abstract and final,

  Line 13 : Cannot override the final method.

Predict the output:

• welcome

  10

  20

• Error in Line 2 : Modifier static not allowed here.

• Error in Line 7: Modifier static not allowed here.

• Compilation Error in both Line 2 and Line 7.

Which one of the below options is correct as per the given piece of code?

• SIMRAN

• Compilation error : Final variable should be initialized before starting the execution.

• Compilation error : Java does not allow final keyword before the constructor.

• Compilation error : this keyword cannot be used with final variable.

Predict the output:

• Application Successful

• Application Successful

  Method C

• Compilation Error at Line 7 : Cannot extend multiple interfaces.

• Compilation Error at Line 10 : Add unimplemented methods.

Identify the lines that can be replaced at /*Insert code here.*/ in the given code to display 100 successfully:

1. Testable.testValue;

2. Test.Testable.testValue;

3. Test.testValue;

4. new Test().testValue;

• Option 1 and 2.

• Option 2 and 3.

• Option 1, 3 & 4.

• All the four options.

Predict the output:

• NullPointerException

• 9

• 5

• None of the above

Which one of the following statements will import all the classes from java.util package?

• import java.*;

• import *.*;

• import java.util.*;

• import java.util;

Which of the following access specifiers can be used with a class so that it is visible only within the same package?

• public

• No Access Specifiers

• protected

• private

Which of the below statements are true about interfaces?

Statement 1: An interface cannot be instantiated.

Statement 2: An interface cannot contain any constructors.

Statement 3: An interface cannot contain instance variables.

• Statement 1 ,2 & 3 are true

• Statement 1 & 2 are true

• Statement 1 & 3 are true

• All the statements are false