Question

Part I (20%) [File: Student.java]

Create a class called Student that has the following stored properties:

• StudentID
• First Name
• Last Name

Class Student should have read/write properties, constructor(s) and should implement the Academic interface. For academic methods, return zero for average, zero for credits and false for graduate. Also implement the toString() method that returns the above information as a String.

Part II (5%) [File: Academic.java]
Create an interface Academic that declares three methods:
1. average - that returns the average grade for students
2. credits – returns the number of credits that students have.
3. graduate – Boolean that returns true if the student is eligible to graduate.

Part III (25%) [File: UndergraduateStudent.java]
Create a class called UndergraduateStudent that inherits from Student and has the following members:

• grades – array of student marks for each course

Class UndergraduateStudent should have read/write property, constructors(s) and should override the description property. It should also implement the Academic interface. Undergraduate student get 0.5 credits per course and are eligible to graduate if they have 10 credits. They can only receive a credit if their mark for a course is 50% or higher. It should override the toString() method as well.

Part IV (25%) [File: GraduateStudent.java]
Create a class called GraduateStudent that inherits from Student and has the following members:

• grades - array of student marks for each course
• thesis – description of thesis (String type)
• weeklyHours – number of hours teaching per week

Class GraduateStudent should have read/write properties, constructor(s) and should override the toString() method. It should also implement the Academic interface. Graduate student gets 1.0 credits per course and is eligible to graduate if they have 6 credits. They can only receive a credit if their mark for a course is 60% or higher.


Part VI (25%) [File: main.java]

Create an array that can hold Student objects. Populate this array with 6 objects (3 of UndergraduateStudent and 3 of GraduateStudent objects).

Sort and display the students based on credits earned from high to low and by average from high to low. Also display all other relevant information including availability to graduate.

Answer 1

Academic.java

public interface Academic {

   double average();
   double credits();
   boolean graduate();
}

Student.java

public class Student implements Academic{
  
   int studentID;
   String firstName;
   String lastName;
  
  

   @Override
   public String toString() {
       return "Student [studentID=" + studentID + ", firstName=" + firstName + ", lastName=" + lastName + "]";
   }

   public Student(int studentID, String firstName, String lastName) {
       super();
       this.studentID = studentID;
       this.firstName = firstName;
       this.lastName = lastName;
   }
  
  

   public int getStudentID() {
       return studentID;
   }

   public void setStudentID(int studentID) {
       this.studentID = studentID;
   }

   public String getFirstName() {
       return firstName;
   }

   public void setFirstName(String firstName) {
       this.firstName = firstName;
   }

   public String getLastName() {
       return lastName;
   }

   public void setLastName(String lastName) {
       this.lastName = lastName;
   }

   @Override
   public double average() {
       // TODO Auto-generated method stub
       return 0;
   }

   @Override
   public double credits() {
       // TODO Auto-generated method stub
       return 0;
   }

   @Override
   public boolean graduate() {
       // TODO Auto-generated method stub
       return false;
   }

   public int compareTo(UnderGraduateStudent arg0) {
       // TODO Auto-generated method stub
       return 0;
   }

   public void setGrades(double[] grades) {
       // TODO Auto-generated method stub
      
   }
  
  

}

UnderGraduateStudent.java

import java.util.Arrays;

public class UnderGraduateStudent extends Student{
  
   double[] grades;

   public UnderGraduateStudent(int studentID, String firstName, String lastName,double[] grades) {
       super(studentID, firstName, lastName);
       this.grades = grades;
       // TODO Auto-generated constructor stub
   }

  

   public double[] getGrades() {
       return grades;
   }

   public void setGrades(double[] grades) {
       this.grades = grades;
   }

   @Override
   public String toString() {
       return super.toString()+"UnderGraduateStudent [grades=" + Arrays.toString(grades) + "]";
   }
  
  
   @Override
   public double average() {
       // TODO Auto-generated method stub
       double sum =0;
       for(int i=0;i<grades.length;i++)
           sum = sum + grades[i];
      
      
       return sum/grades.length;
   }

   @Override
   public double credits() {
       // TODO Auto-generated method stub
       double credit = 0;
      
       for(int i=0;i<grades.length;i++) {
           if(grades[i]>=50)
               credit = credit + 0.5;
       }
       return credit;
   }

   @Override
   public boolean graduate() {
       // TODO Auto-generated method stub
      
       double credit = credits();
      
       if(credit>=10)
           return true;
      
       return false;
   }

}

GraduateStudent.java

import java.util.Arrays;

public class GraduateStudent extends Student{
  
   double[] grades;

   public GraduateStudent(int studentID, String firstName, String lastName,double[] grades) {
       super(studentID, firstName, lastName);
       this.grades = grades;
       // TODO Auto-generated constructor stub
   }

   public double[] getGrades() {
       return grades;
   }

   public void setGrades(double[] grades) {
       this.grades = grades;
   }
  
  

   @Override
   public double average() {
       // TODO Auto-generated method stub
       double sum =0;
       for(int i=0;i<grades.length;i++)
           sum = sum + grades[i];
      
      
       return sum/grades.length;
   }

   @Override
   public double credits() {
       // TODO Auto-generated method stub
       double credit = 0;
      
       for(int i=0;i<grades.length;i++) {
           if(grades[i]>=60)
               credit = credit + 1;
       }
       return credit;
   }

   @Override
   public boolean graduate() {
       // TODO Auto-generated method stub
      
       double credit = credits();
      
       if(credit>=6)
           return true;
      
       return false;
   }

   @Override
   public String toString() {
       return super.toString()+"GraduateStudent [grades=" + Arrays.toString(grades) + "]";
   }
  
  
  
  
  

}

Main..java

import java.util.Arrays;

public class Main {

   public static void main(String[] args) {
       // TODO Auto-generated method stub

       Student students[] = new Student[6];

       // Under Graduate Students
      
       double[] grades = { 10, 20, 30, 40, 60, 70, 80, 40, 90 };

       students[0] = new UnderGraduateStudent(1, "john", "Victor",grades);
      
      
       double[] grades1={60,70,80,40,90,60,70,80,20,90,100};

       students[1] = new UnderGraduateStudent(2, "john", "Jashuar",grades1);
      
       double[] grades2={60,70,80,40,90,60,70,80,20,90,100,60,50,60,67,87,58,74,57,57,78.98,98,77,76,86,79,58,37,80,98.89,70,98};

       students[2] = new UnderGraduateStudent(2, "betal", "Jeshan",grades2);
      
       // Graduate Students
      
       double[] grades3 = { 10, 20, 30, 40, 60, 70, 80, 40, 90 };

       students[3] = new GraduateStudent(1, "john", "blaker",grades3);

       double[] grades4={60,70,80,40,90,60,70,80,20,90,100};

       students[4] = new GraduateStudent(2, "guita", "Blake",grades4);
      
       double[] grades5={60,70,80,40,90,60,70,80,20,90,100,60,50,60,67,87,58,74,57,57,78.98,98,77,76,86,79,58,37,80,98.89,70,98};

       students[5] = new GraduateStudent(2, "john", "JPeterr",grades5);
      
      
      
      
       for (int i = 0; i < 6; i++)
{
for (int j = i + 1; j < 6; j++)
{
if (students[i].credits() > students[j].credits())
{
Student temp = students[i];
students[i] = students[j];
students[j] = temp;
}
}
}
      
      
       for(int i=0;i<6;i++) {
           System.out.println(students[i].toString());
           System.out.println("Number of credits is "+ students[i].credits());
           System.out.println("Graduate status is "+students[i].graduate());
          
       }
         
      
      
   }

}

Output

Student [studentID=1, firstName=john, lastName=Victor]UnderGraduateStudent [grades=[10.0, 20.0, 30.0, 40.0, 60.0, 70.0, 80.0, 40.0, 90.0]]
Number of credits is 2.0
Graduate status is false
Student [studentID=1, firstName=john, lastName=blaker]GraduateStudent [grades=[10.0, 20.0, 30.0, 40.0, 60.0, 70.0, 80.0, 40.0, 90.0]]
Number of credits is 4.0
Graduate status is false
Student [studentID=2, firstName=john, lastName=Jashuar]UnderGraduateStudent [grades=[60.0, 70.0, 80.0, 40.0, 90.0, 60.0, 70.0, 80.0, 20.0, 90.0, 100.0]]
Number of credits is 4.5
Graduate status is false
Student [studentID=2, firstName=guita, lastName=Blake]GraduateStudent [grades=[60.0, 70.0, 80.0, 40.0, 90.0, 60.0, 70.0, 80.0, 20.0, 90.0, 100.0]]
Number of credits is 9.0
Graduate status is true
Student [studentID=2, firstName=betal, lastName=Jeshan]UnderGraduateStudent [grades=[60.0, 70.0, 80.0, 40.0, 90.0, 60.0, 70.0, 80.0, 20.0, 90.0, 100.0, 60.0, 50.0, 60.0, 67.0, 87.0, 58.0, 74.0, 57.0, 57.0, 78.98, 98.0, 77.0, 76.0, 86.0, 79.0, 58.0, 37.0, 80.0, 98.89, 70.0, 98.0]]
Number of credits is 14.5
Graduate status is true
Student [studentID=2, firstName=john, lastName=JPeterr]GraduateStudent [grades=[60.0, 70.0, 80.0, 40.0, 90.0, 60.0, 70.0, 80.0, 20.0, 90.0, 100.0, 60.0, 50.0, 60.0, 67.0, 87.0, 58.0, 74.0, 57.0, 57.0, 78.98, 98.0, 77.0, 76.0, 86.0, 79.0, 58.0, 37.0, 80.0, 98.89, 70.0, 98.0]]
Number of credits is 24.0
Graduate status is true

Answer 2

//Student.java

package Test.main;

public class Student implements Academic {

public long studentID;

public String fName;

public String lName;

public Student(long studentID, String fName, String lName) {

this.studentID = studentID;

this.fName = fName;

this.lName = lName;

}

public double Average() {

return 0;

}

public double Credits() {

return 0;

}

public boolean Graduate() {

return false;

}

public String toString() {

return fName + " "+ lName +" " + studentID ;

}

}

//UnderGraduate.java

package Test.main;

public class UndergraduateStudent extends Student{

int[] grades= new int[20];

UndergraduateStudent(long studentID, String fName, String lName,int grades[]) {

super(studentID,fName,lName);

this.grades = grades;

}

public double Average() {

int numberofCourses = grades.length;

double average = 0;

for(int i=0;i<numberofCourses;i++) {

average += grades[i];

}

return average/numberofCourses;

}

public double Credits() {

int numberofCourses = grades.length;

double credits = 0;

for(int i=0;i<numberofCourses;i++) {

if(grades[i]>50)

credits+=0.5;

}

return credits;

}

public boolean Graduate() {

if(Credits()>=10)

return true;

return false;

}

public String toString() {

return super.toString() + grades;

}

}

//Graduate.java

package Test.main;

public class GraduateStudent extends Student{

int grades[];

String thesis;

int weeklyHours;

GraduateStudent(long studentID, String fName, String lName,int grades[], String thesis, int weeklyHours) {

super(studentID,fName,lName);

this.grades = grades;

this.thesis = thesis;

this.weeklyHours = weeklyHours;

}

public double Average() {

int numberofCourses = grades.length;

double average = 0;

for(int i=0;i<numberofCourses;i++) {

average += grades[i];

}

return average/numberofCourses;

}

public double Credits() {

int numberofCourses = grades.length;

double credits = 0;

for(int i=0;i<numberofCourses;i++) {

if(grades[i]>60)

credits++;

}

return credits;

}

public boolean Graduate() {

if(Credits()>=6)

return true;

return false;

}

public String toString() {

return super.toString() + grades+ "" +thesis+ "" + weeklyHours;

}

}

//Main.java

package Test.main;

import java.util.*;

import java.io.*;

interface Academic{

double Average();

double Credits();

boolean Graduate();

String toString();

}

public class Main {

public static void main(String args[]) {

UndergraduateStudent [] UG;

UG = new UndergraduateStudent[3];

int grades1[] = new int[] {48,49,50,52,53,43,78,67,76,56,48,82,81,71,61,61,83,84,74,74};

int grades2[] = new int[] {90,89,50,52,53,43,78,67,76,56,48,82,81,71,61,61,83,84,74,74};

int grades3[] = new int[] {77,78,50,52,53,43,78,67,76,56,48,82,81,71,61,61,83,84,74,74};

UG[0] = new UndergraduateStudent(123, "James" , "Bond" , grades1);

UG[1] = new UndergraduateStudent(456, "Lord" , "Snow" , grades2 );

UG[2] = new UndergraduateStudent(789, "Tom" , "Cruise", grades3);

GraduateStudent [] G;

G = new GraduateStudent[3];

int grades4[] = new int[] {52,53,43,78,67,76,56,48,82,81};

int grades5[] = new int[] {50,52,53,43,78,67,76,56,48,82};

int grades6[] = new int[] {77,78,50,52,53,43,78,67,76,56};

G[0] = new GraduateStudent(112, "Robin", "Singh", grades4, "Recognition System", 20);

G[1] = new GraduateStudent(112, "Sachin", "Ramesh", grades5, "Recommendation System",40);

G[2] = new GraduateStudent(112, "Virendra", "Sehwag", grades6, "Mobile System",30);

double [] avg;

avg = UG.Average();

double [] crd;

crd = UG.Credits;

Arrays.sort(avg);

Arrays.Sort(crd);

double [] avg1;

avg1 = UG.Average();

double [] crd1;

crd1 = UG.Credits;

Arrays.sort(avg1);

Arrays.Sort(crd1);

System.out.printf("Modified arr[] : %s", Arrays.toString(UG));

System.out.printf("Modified arr[] : %s", Arrays.toString(G));

}

}