Question

Java Programming Language

Edit and modify from the given code

1. Perform the exact same logic, except . . .
2. The numeric ranges and corresponding letter grade will be stored in a file.
3. Need error checking for:
   1. Being able to open the text file.
   2. The data makes sense: 1 text line of data would be 100 = A.
4. Read in all of the numeric grades and letter grades and stored them into an array or arraylist.
5. Then do the same logic.
6. The handing of the invalid numeric value should display the same message.
7. The output for the grade letter should look the same.

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

//Given code

import java.util.*;

public class LetterGrades {
    public static void main(String[] args) {

        //Get the user input
        Scanner sc = new Scanner(System.in);

        //Array List
        ArrayList<Double> scores=new ArrayList<Double>();
        ArrayList<String> gradeLetters=new ArrayList<String>();
        String gradeLetter="";

        //Loop
        while(true)
        {
            System.out.print("Enter your numeric grade (enter -1 to end and view the result): ");
            double grade = sc.nextDouble();

            //End the program if user entered -1
            if(grade == -1)
            {
                System.out.print("The program ended");
                break;
            }

            //validating the grade between 0 and 100
            if(grade<0 || grade>100)//if user entered invalid input
            {
                while(true)//infinity loop to read input untill user enter valid input.
                {
                    //Displaying error message.
                    System.out.print("You entered inalid numeric grade.");
                    System.out.print("Please enter valid numeric grade from 0-100: ");
                    grade = sc.nextDouble();
                    //End the validating loop if user entered valid input.
                    if(grade>=0 && grade<=100)
                    {
                        break;
                    }
                }
            }
            scores.add(grade);
            //Convert numeric grade to letter grade
            if(grade>=93 && grade<=100)
                gradeLetter="A";
            else if(grade>=90 && grade<93)
                gradeLetter="A-";

            else if(grade>=87 && grade<90)
                gradeLetter="B+";
            else if(grade>=83 && grade<87)
                gradeLetter="B";
            else if(grade>=80 && grade<83)
                gradeLetter="B-";

            else if(grade>=73 && grade<80)
                gradeLetter="C+";
            else if(grade>=70 && grade<73)
                gradeLetter="C";

            else if(grade>=60 && grade<70)
                gradeLetter="D";

            else if(grade<60)
                gradeLetter="F";
            gradeLetters.add(gradeLetter);
        }

        for(int i=0;i<scores.size();i++)
        {
            System.out.println("\nScore :"+scores.get(i));
            System.out.println("Letter Grade :"+gradeLetters.get(i));

        }
    }
}

Answer 1

If you have any doubts, please give me comment...

import java.io.*;

import java.util.*;

public class LetterGrades {

public static void main(String[] args) throws FileNotFoundException {

// Get the user input

Scanner sc = new Scanner(System.in);

// Array List

ArrayList<Double> scores = new ArrayList<Double>();

ArrayList<String> gradeLetters = new ArrayList<String>();

String gradeLetter = "";

// Loop

while (true) {

System.out.print("Enter your numeric grade (enter -1 to end and view the result): ");

double grade = sc.nextDouble();

// End the program if user entered -1

if (grade == -1) {

System.out.print("The program ended");

break;

}

// validating the grade between 0 and 100

if (grade < 0 || grade > 100)// if user entered invalid input

{

while (true)// infinity loop to read input untill user enter valid input.

{

// Displaying error message.

System.out.print("You entered inalid numeric grade.");

System.out.print("Please enter valid numeric grade from 0-100: ");

grade = sc.nextDouble();

// End the validating loop if user entered valid input.

if (grade >= 0 && grade <= 100) {

break;

}

}

}

scores.add(grade);

// Convert numeric grade to letter grade

if (grade >= 93 && grade <= 100)

gradeLetter = "A";

else if (grade >= 90 && grade < 93)

gradeLetter = "A-";

else if (grade >= 87 && grade < 90)

gradeLetter = "B+";

else if (grade >= 83 && grade < 87)

gradeLetter = "B";

else if (grade >= 80 && grade < 83)

gradeLetter = "B-";

else if (grade >= 73 && grade < 80)

gradeLetter = "C+";

else if (grade >= 70 && grade < 73)

gradeLetter = "C";

else if (grade >= 60 && grade < 70)

gradeLetter = "D";

else if (grade < 60)

gradeLetter = "F";

gradeLetters.add(gradeLetter);

}

PrintWriter pw = new PrintWriter(new File("output.txt"));

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

System.out.println("\nScore :" + scores.get(i));

System.out.println("Letter Grade :" + gradeLetters.get(i));

pw.println(scores.get(i)+" = "+gradeLetters.get(i));

}

pw.close();

}

}