Question

Implement a superclass Person. Make two classes, Student and Instructor, that inherit from Person. A person has a name and a year of birth. A student has a major, and an instructor has a salary. Write the class declarations, the constructors, and the methods toString for all classes. Supply a test program that tests these classes and methods.

1. Add a method
   Public static Measurable max(Measurable[ ] objects)
   to the Data class that returns the object with the largest measure.
2. Implement a class Quiz that implements the Measurable interface (in Slide 6 of Chapter 10). A quiz has a score and a letter grade (such as B+). Supply a test program QuizTester that uses the Data class in a) to process an array of quizzes and display the average score and the quiz with the highest score (both letter grade and score).

3. (Chapter 10, 30 points) Supply a class Person that implements the Comparable interface. Compare persons by their name. Ask the user to input ten names and generate ten Person objects. Using the compareTo method, determine the first and last person among them (in lexicographic order) and print them.

Answer 1

Question 1:  
---------------------------------------------------
file-name:     Person.java
-----------------------------------------------------
public class Person {
    String personName;
    int year;

    Person(String name, int year) {
        this.personName = name;
        this.year = year;
    } // END of constructor

    public String getPersonName() {
        return personName;
    }
    public int getYear() {
        return year;
    }

    public String toString() {

        String str = "\nName: "+getPersonName() +
                "\nBirth year: "+getYear();

        return str;
    }
} // END of class

-----------------------------------------------------------------------------------------------------------------------------------

file-name:   Student.java
---------------------------
public class Student extends Person {
    String major;

    Student(String name, int year, String major) {
        super(name,year);
        this.major = major;
    } //END of constructor

    public String getMajor() {
        return major;
    }

    @Override
    public String toString() {
        System.out.println(super.toString());
        String str = "Major: "+getMajor();

        return str;
    }
} // END of class

--------------------------------------------------------------------------------------------------------------------------------------------------

file-name:   Instructor.java
---------------------------------
public class Instructor extends Person {
    int salary;

    Instructor(String name, int year, int salary) {
        super(name,year);
        this.salary = salary;
    } // END of constructor

    public int getSalary() {
        return salary;
    }

    public String toString() {
        System.out.println(super.toString());
        String str = "Salary: "+getSalary();

        return str;
    }
} // END of Instructor class

-----------------------------------------------------------------------------------------------------------------------------------------------------------

file-name:   Main.java
--------------------------------
public class Main {
    public static void main(String[] args) {

        Person p = new Person("John",1985);
        Student s = new Student("Balayya",1976,"CSE");
        Instructor i = new Instructor("Chiranjeevi",1967,25000);

        System.out.println(p);
        System.out.println(s);
        System.out.println(i);
    } // END of main( )
} // END of Main class

------------------------------------------------

OUTPUT:

________________________________________________________________________________________________________________________________________

NOTE:   Person class using Comparable interface.
--------------------------------------------------
file-name:   Person.java
--------------------------
public class Person implements Comparable<Person> {
    String personName;
    int year;

    Person(String name, int year) {
        this.personName = name;
        this.year = year;
    } // END of constructor

    public String getPersonName() {
        return personName;
    }
    public int getYear() {
        return year;
    }

    public String toString() {

        String str = "Name: "+getPersonName() +
                "\nBirth year: "+getYear();

        return str;
    }

    public int compareTo(Person p) {
        return this.getPersonName().compareTo(p.getPersonName());
    }
} // END of class

-------------------------------------------------------------------------------------------------------------------------

file-name:   Main.java
--------------------------
public class Main {
    public static void main(String[] args) {

        // creating an array of size 10, to store person objects.
        Person[] people = new Person[10];

        people[0] = new Person("John",1985);
        people[1] = new Person("Kiran",1995);
        people[2] = new Person("Chiranjeevi",1969);
        people[3] = new Person("Nagarjuna",1965);
        people[4] = new Person("Pawan kalyan",2005);
        people[5] = new Person("Prabhas",2015);
        people[6] = new Person("Shourya",2000);
        people[7] = new Person("NTR",1999);
        people[8] = new Person("Rajnikanth",1985);
        people[9] = new Person("Agasthya",1979);

        System.out.println("\nArray before sorting: ");

        for(int i=0; i<people.length; i++) {
            System.out.print(people[i].getPersonName()+" ");
        }

        // sorting the array
        //  using Bubble sort to sort the array
        for( int i=1; i < people.length; i++ ) {
            for(int j=0; j<people.length - i; j++) {

                if( (people[j].getPersonName().compareTo(people[j+1].getPersonName())) > 0 ) {

                    // swapping
                    Person temp = people[j];
                    people[j] = people[j+1];
                    people[j+1] = temp;
                }
            }
        }

//        System.out.println("\nAfter sorting: ");
//        for(int i=0; i<people.length; i++) {
//            System.out.print(people[i].getPersonName()+" ");
//        }

        System.out.println("\nFirst Name in the array: ");
        System.out.println(people[0]);
        System.out.println("Last Name in the array: ");
        System.out.println(people[people.length-1]);

    } // END of main( )
} // END of Main class

--------------------------------------------------------------------------------------------

OUTPUT:

___________________________________________________________________________________________________________________________________________________________________

Hey, I found some difficulty in understanding a,b problems. Please can you provide more details about data class , and what should be written in Measurable interface.

I will implement those as soon as you provide the required data.

Thank You!!