Chapter 7, Problem 7.1PE

(Assign grades) Write a program that reads student scores, gets the best score, and then assigns grades based on the following scheme:

Grade is A if score is ≥ best −10;

Grade is B if score is ≥ best −20;

Grade is C if score is ≥ best −30;

Grade is D if score is ≥ best − 40;

Grade is F otherwise.

The program prompts the user to enter the total number of students, then prompts the user to enter all of the scores, and concludes by displaying the grades. Here is a sample run:

Program Plan Intro

Assign Grades

Program Plan:

• Import required packages.
• Declare the main class method “Sample1”.
  • In the main method.
    • Create an object “input” for the scanner class.
    • Get the number of students from the user and store it in a variable “numberOfStudents”.
    • Create an object “scores” for the static method “double”.
    • Read the corresponding student scores and find the best score.
    • Declare and initialize the output string.
    • Print the student score and grade.
  • The grades are assigned based on the following scheme.
    • Grade is A if score is >= best-10;
    • Grade is B if score is >= best -20;
    • Grade is C if score is >= best -30;
    • Grade is D if score is >= best - 40;
    • Grade is F otherwise.

Program Description Answer

The below program reads the total number of students and their scores and then display the grade of each student.

Explanation of Solution

Program:

//Import required packages

import java.io.*;

import java.util.Scanner;

/*

 * To change this template, choose Tools | Templates

 * and open the template in the editor.

 */

//Class name

public class sample1 {

// Main Method

public static void main(String[] args) {

// Create a Scanner

Scanner input = new Scanner(System.in);

// Get the number of students

System.out.print("Enter the number of students: ");

int numberOfStudents = input.nextInt();

//Create an object for the static method

double[] scores = new double[numberOfStudents]; // Array scores

double best = 0; // The best score

// Read scores and find the best score

System.out.print("Enter " + numberOfStudents + " scores: ");

for (int i = 0; i < scores.length; i++) {

scores[i] = input.nextDouble();

if (scores[i] > best)

best = scores[i];

}

// Declare and initialize output string

char grade; // The grade

// Assign and display grades

for (int i = 0; i < scores.length; i++) {

if (scores[i] >= best - 10)

grade = 'A';

else if (scores[i] >= best - 20)

grade = 'B';

else if (scores[i] >= best - 30)

grade = 'C';

else if (scores[i] >= best - 40)

grade = 'D';

else

grade = 'F';

//Print the output

System.out.println("Student " + i + " score is " + scores[i]+ " and grade is " + grade);

}

}

}

Sample Output

Enter the number of students: 5

Enter 5 scores: 78 92 69 45 56

Student 0 score is 78.0 and grade is B

Student 1 score is 92.0 and grade is A

Student 2 score is 69.0 and grade is C

Student 3 score is 45.0 and grade is F

Student 4 score is 56.0 and grade is D