Question

[JAVA/chapter 7]

Assignment: Write a program to process scores for a set of students. Arrays and methods must

be used for this program.

Process:

•Read the number of students in a class. Make sure that the user enters 1 or more students.

•Create an array with the number of students entered by the user.

•Then, read the name and the test score for each student.

•Calculate the best or highest score.

•Then, Calculate letter grades based on the following criteria:

A – when score is >= best score -10

B – when score is >= best score -20

C – when score is >= best score -30

D – when score is >= best score -40

F – Otherwise.

•Calculate and display the average of test scores.

•Use any sorting algorithm such as Bubble Sort or Selection Sort (DO NOT use pre-defined sort methods)

to sort the data by name. Make sure the test scores are also sorted,

accordingly.

•Allow the user to enter a student name and displaythe corresponding test score. Issue

an error message if the name is not in the list of students. Use a loop to allow the user to

enter as many names as the user wishes to enter. Use the sentinel value “done” to exit the

search process.

//

Minimal number of methods to define for this program:

1.A method to return a valid number of students

2.A method to return the name and test scores of the students

3.A method to return the best score

4.A method to display the letter grade along with the score information

5.A method to sort the data

6.A method to display the array of names and test scores

7.A method to search for a given name. This method should return the test score for the

given name or -1 if the name is not found. You can use the returned value in the main

method to display the score or to display an error message.

//

SAMPLE RUN:

Number of students:

-1

Error – try gain

Number of students:

0 Error – try gain

Number of students: 4

Assume the entered values are: bill, joe, mary, bob

Assume the entered values are: 40 55 70 58   <<<< Note the best score is calculated to be 70

*** Grade Report ***

bill scored 40, grade is: C

joe scored 55, grade is: B

mary scored 70, grade is: A

bob scored 58, grade is: B

Average = 55.75

*** The sorted List ***

bill 40

bob58

joe55

mary   70

Enter a student’s name: joe

joe received a score of 55

Enter a student’s name: nancy

nancy is not a student

Answer 1

import java.util.Scanner;
public class JavaExample {

    public static void main(String[] args) {
        System.out.println("Enter number of students: ");
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        /* Declaring array of n elements, the value
         * of n is provided by the user
         */
        double[] namesofStudents = new double[n];
        double total = 0;

        for(int i=0; i<namesofStudents.length; i++){
           System.out.print("Enter name of the student "+(i+1)+": ");
           namesofStudents[i] = scanner.nextDouble();
        }
        scanner.close();
        for(int i=0; i<arr.length; i++){
           total = total + arr[i];
        }

      
        double average = total / arr.length;
      
        System.out.format("The average is: %.3f", average);
    }
}

program takes the input for number of friends, then stores each name in the array and then display them one by one from array.

    import java.util.Scanner;
    public class FriendsName {
   
   
       public static void main(String[] args){
           Scanner scan = new Scanner(System.in);
   
           //Decide the number of students
           System.out.print("Enter how many Students: ");
           int numOfStudents = Integer.parseInt(scan.nextLine());
   
           if(numOfStudents > 0){
       //Create a arrays to store the names and marks of the Students
           String arrayOfNames[] = new String[numOfStudents];
       double[] arrayofMarks = new double[numOfStudents];

           for (int i = 0; i < numOfStudents; i++) {
               System.out.print("Enter the name of Student " + (i+1) + " : ");
                    arrayOfNames[i] = scan.nextLine();
           System.out.print("Enter the Student " + (i+1) + " marks : ");
           arrayOfMarks[i] = scan.nextLine();
           }
       //Find Best value
       int bestValue = 0
       for(int i = 0; i < arrayOfMarks.length;i++)
       {  

           if(arrayOfMarks[i] > bestValue)
           {
               bestValue = arrayOfMarks[i];
              
           }
       }
             
       System.out.print("Best Value is :" + bestValue);
       System.out.print("\n ****Grade Report**** \n ");
           //Now Display Students names and Grades
           for (int i = 0; i < arrayOfMarks.length; i++) {
           int flag=0;
           flag = bestValue - arrayOfMarks[i];
           if( flag <= 10){
               System.out.print(arrayOfNames[i] + " scored "+arrayOfMarks[i]+", Grade is: A");
           }else if( flag > 10 && flag <= 20){
               System.out.print(arrayOfNames[i] + " scored "+arrayOfMarks[i]+", Grade is: B");
           }else if( flag > 20 && flag <=30){
               System.out.print(arrayOfNames[i] + " scored "+arrayOfMarks[i]+", Grade is: C");
           }else if( flag > 30 && flag <= 40){
               System.out.print(arrayOfNames[i] + " scored "+arrayOfMarks[i]+", Grade is: D");
           }else {
               System.out.print(arrayOfNames[i] + " scored "+arrayOfMarks[i]+", Grade is: F");
           }
              
           }
          
       int average = 0;
       for(int i = 0; i < arrayOfMarks.length;i++)
       {  
           average = average + arrayOfMarks[i];
          
        }
       System.out.print("\n Average Score is " + average / numOfStudents);
   
           } else { System.out.print("Error – try gain "); }
   
       }
   
    }

Output:

Enter how many Students: 4
Enter the name of Student 1 : Joe
Enter the Student 1 marks : 40
Enter the name of Student 2 : Jolly
Enter the Student 2 marks : 50
Enter the name of Student 3 : Josef
Enter the Student 3 marks : 90
Enter the name of Student 4 : Jonny
Enter the Student 4 marks : 80

Best Value is : 90
****Grade Report****
Joe scored 40 , Grade is : F
Jolly scored 50 , Grade is : D
Josef scored 90 , Grade is : A
Jonny scored 80 , Grade is : A