Practice Set: Unit-4

                                                       
                                                        Practice Set: Unit 4

1. What are the uses of super keyword in Java? Explain with a suitable example.

2. What are the various uses of final keyword in java? An abstract method can not be declared final. Why?

3. Differentiate between Abstract class and Interface. What do you mean by Functional interface and Lambda Expression?          

4. Define Anonymous class. Why we use anonymous class in Java?  

5. Differentiate between static nested class and inner class in java.

6. Write a program to define a class named Demo which contains a local class named MyLocal inside its constructor. Define a method sayHello (String XXX) to display Hello XXX (e.g Hello Ravi if name is Ravi).

Define a class named TestLocal which reads the name from the user and then invoke the sayHello method of MyLocal class.  

7. Complete the following program as per comments.
abstract class A
  {
abstract void x();
abstract void y();
  }
class UseAbstract
  {
/*Use anonymous class to define and call methods of abstract class A*/
  }
      
8. Create a functional interface Predicate with an abstract method test with following signature:
            boolean test(String t);
Write a test program to check a string contains character 'c' or not by using above test method with the help of lambda expression.

9. Write a program to define an interface Testing which contains an abstract method
boolean checkString(String str)

Create a class Input which must contain a method String getInput(Testing obj) which prompts the user to enter a String and the String must be checked using the checkString such that it returns TRUE only when the String contains all the vowels. If input is correct then display “String Accepted” otherwise ask to re-enter the String.

10. Write a program to create a class Employee with appropriate fields for employee name, employee id and Vehicle.
Vehicle is a nested class with attributes vehicle number and owner name. An employee may or may not have a vehicle.
Create at least 3 employee objects using appropriate constructor and store the employee objects in a collection.
Implement a method getVehicleDetails(String Vehicle_number) to display the name and id of the employee who own that vehicle.