Write a program with while loop code in it to calculate the amount of exam scores enter by a user

Question

I wrote a program for the following question in a task I'm doing.

"Write a program to read a list of exam scores given as integer percentages in the range 0 to 100. Display the total number of grades and the number of grades in each letter-grade category as follows: 90-100 is A, 80-89 is B, 70-79 is C, 60-69 is D, and 0-59 is F. Use negative score as a sentinel value to indicate the end of the input."

For Example, input: 98,87,86,85,85,78,73,72,72,70,66,63,50,-1

Output should be:

Total number of grades entered was 13

A's =1

B's=4

C's=5

D's=2

F's=1

//This is the code I wrote.// 
import java.util.Scanner;
public class grade
 {
public static void main(String[] args)
 {
        int A_grades = 0;
        int B_grades = 0;
        int C_grades = 0;
        int D_grades = 0;
        int F_grades = 0;
        int count=0;
        Scanner in = new Scanner(System.in);
        System.out.println("Enter exam score as integer percentage in range 0 to 100 :");
        int score = in.nextInt();
 while(score>0)
 {
       count++;
 if(score>=90 && score<=100)
        A_grades++;
    else if(score>=80 && score<=89)
        B_grades++;
    else if(score>=70 && score<=79)
        C_grades++;
    else if(score>=60 && score<=69)
        D_grades++;
    else if(score>=0 && score<=59)
        F_grades++;
    System.out.println("Enter exam score as integer percentage in range 0 to 100 :");
 score = in.nextInt();
 } //end while
 System.out.println("Total number of grades :"+ count);
 System.out.println("Total number of A grades :"+ A_grades);
 System.out.println("Total number of B grades :"+ B_grades);
 System.out.println("Total number of C grades :"+ C_grades);
 System.out.println("Total number of D grades :"+ D_grades);
 System.out.println("Total number of F grades :"+ F_grades);
 } // end main
 } // end class

Below is the Output of the program.

Enter exam score as integer percentage in range 0 to 100 :

88 98 78 68 55 45 -1

Enter exam score as integer percentage in range 0 to 100 :

Enter exam score as integer percentage in range 0 to 100 :

Enter exam score as integer percentage in range 0 to 100 :

Enter exam score as integer percentage in range 0 to 100 :

Enter exam score as integer percentage in range 0 to 100 :

Enter exam score as integer percentage in range 0 to 100 :

Total number of grades :6

Total number of A grades :1

Total number of B grades :1

Total number of C grades :1

Total number of D grades :1

Total number of F grades :2

In the output it keeps repeating "Enter exam score as integer percentage in range 0 to 100 :"

How can I write the code to only show it once?

Answer 1

Remove System.out.println("Enter exam score as integer percentage in range 0 to 100 :"); from your loop if you don't want to see this message multiple times.

Answer 2

the reason it is continuously printing that out is because the "Scanner" class that you are using does not pause for input.

I would suggest that you use a BufferedReader.

I assume that you need to ask the user to enter a value each time. So if you remove the text to solve the multiple display issue, the user wont be given the message.

I have attached a snippet of the code, with a BufferedReader that will solve your problem:

---

 //This is the code I wrote.// import java.util.Scanner; import java.io.*; import java.io.BufferedReader; import java.util.*; public class Grade{ public static void main(String[] args){ int A_grades = 0; int B_grades = 0; int C_grades = 0; int D_grades = 0; int F_grades = 0; int count=0; try{ //Scanner in = new Scanner(System.in); BufferedReader br = new BufferedReader(new InputStreamReader(System.in) ); System.out.println("Enter exam score as integer percentage in range 0 to 100 :"); int score = Integer.parseInt(br.readLine()); while(score>0){ count++; if(score>=90 && score<=100) A_grades++; else if(score>=80 && score<=89) B_grades++; else if(score>=70 && score<=79) C_grades++; else if(score>=60 && score<=69) D_grades++; else if(score>=0 && score<=59) F_grades++; System.out.println("Enter exam score as integer percentage in range 0 to 100 :"); score = Integer.parseInt(br.readLine()); } //end while }catch(IOException ioe){} System.out.println("Total number of grades :"+ count); System.out.println("Total number of A grades :"+ A_grades); System.out.println("Total number of B grades :"+ B_grades); System.out.println("Total number of C grades :"+ C_grades); System.out.println("Total number of D grades :"+ D_grades); System.out.println("Total number of F grades :"+ F_grades); } // end main } // end class

---

Hope this helps you and answers your question :)

Let me know of the outcome

Answer 3

Thank you for all the answers.

This is the final code and it works perfectly.

 import java.util.Scanner;
public class grade
 {
 public static void main(String[] args)
 {
        int A_grades = 0;
        int B_grades = 0;
        int C_grades = 0;
        int D_grades = 0;
        int F_grades = 0;
    int count=0;
    Scanner in = new Scanner(System.in);
    System.out.println("Enter exam score as integer percentage in range 0 to 100");
    System.out.println("And enter a negative score at the end of the list :");
    int score = in.nextInt();
 while(score>0)
     {
       count++;
 if(score>=90 && score<=100)
        A_grades++;
    else if(score>=80 && score<=89)
        B_grades++;
    else if(score>=70 && score<=79)
        C_grades++;
    else if(score>=60 && score<=69)
        D_grades++;
    else if(score>=0 && score<=59)
        F_grades++;
    score = in.nextInt();
 } //end while
 System.out.println("Total number of grades :"+ count);
 System.out.println("Total number of A grades :"+ A_grades);
 System.out.println("Total number of B grades :"+ B_grades);
 System.out.println("Total number of C grades :"+ C_grades);
 System.out.println("Total number of D grades :"+ D_grades);
 System.out.println("Total number of F grades :"+ F_grades);
 } // end main
 } // end class