Example questions(10 marks)• Explain the following concepts and illustratehow you can use them with examples.i. Encapsulationii. Information hidingiii. Private helperiv. Polymorphismv. Default constructorExample questions(15 marks)Suppose that a Mammal class written in Java is already available which youcan use (i.e., you are not asked to write this class). This class has instancevariables, constructors and methods as described below:1. instance variables that represent a mammal’s name as a String and themammal’s age as an integer2. a default constructor3. a constructor which is given a mammal’s name as a String and themammal’s age as an integer4. a method set (…) for setting the name and age of a mammal5. a method named printDetails() that prints out the name and the age ofthe mammal6. an equals(…) method which compares the parameter of mammal class tothe current object and returns true if two mammals have the same nameand same ageExample questions• Give Java code for a client program which uses the Mammalclass to do the following. It will create a Mammal object usingthe default constructor. It will then get the name and age of amammal from the user and set the Mammal object to theinput values. The program will then get the name and age of asecond mammal from the user and create the secondmammal object using the non-default constructor. It will thendetermine whether or not the two mammals are the sameand display this information. Finally, the program will print outthe details of the two mammals.

Sure, let's break down the question and answer it step by step.

First, let's explain the concepts:

i. Encapsulation: Encapsulation is one of the four fundamental OOP concepts. It is the technique of making the fields in a class private and providing access to the fields via public methods. For example, in a class Employee, we can make the fields like name, age, and salary as private and provide public methods getName(), getAge(), getSalary() to access these fields.

ii. Information hiding: Information hiding is a principle that reduces the visibility of the software components (like classes, methods etc) to the minimum. It's a way to reduce complexity. For example, when you use a class (like Scanner or System in Java), you don't need to know how these classes are implemented. You just need to know how to use them.

iii. Private helper: A private helper method is a private method that performs a common task for several public methods in the same class. This method cannot be accessed outside of the class. For example, in a class that performs mathematical operations, you might have a private helper method to check if a number is zero.

iv. Polymorphism: Polymorphism is the ability of an object to take on many forms. The most common use of polymorphism in OOP occurs when a parent class reference is used to refer to a child class object. For example, if a parent class named Animal has a method sound(), the subclasses like Dog, Cat can override this method to provide their own implementation.

v. Default constructor: A default constructor is a constructor that doesn't have any parameters. When no constructors are defined in a class, the Java compiler automatically creates a default constructor. For example, in a class Employee, if no constructors are defined, the compiler will create a default constructor like Employee().

Now, let's write the Java code for the client program:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Create a Mammal object using the default constructor
        Mammal mammal1 = new Mammal();

        // Get the name and age of a mammal from the user and set the Mammal object to the input values
        System.out.println("Enter the name and age of the first mammal:");
        mammal1.set(scanner.nextLine(), scanner.nextInt());

        // Get the name and age of a second mammal from the user
        System.out.println("Enter the name and age of the second mammal:");
        scanner.nextLine(); // Consume newline left-over
        String name = scanner.nextLine();
        int age = scanner.nextInt();

        // Create the second mammal object using the non-default constructor
        Mammal mammal2 = new Mammal(name, age);

        // Determine whether or not the two mammals are the same and display this information
        if (mammal1.equals(mammal2)) {
            System.out.println("The two mammals are the same.");
        } else {
            System.out.println("The two mammals are not the same.");
        }

        // Print out the details of the two mammals
        mammal1.printDetails();
        mammal2.printDetails();
    }
}

Please note that this code assumes that the Mammal class and its methods are correctly implemented.