Thread: Trimming, parsing, verifying grades entered are valid

I have been trying to trim the and get the length and parse the string into a double from what the user enters. And I think I may have gotten that? Can you tell me if I did this correctly??

The one that I am most concerned with is how do I validate correct grades to be entered? Any valid grades should be anything greater than 0 and grades less than 100.

So far what Ive done is asked the user to enter up to ten grades, I then added in there, if the user presses enter, then they are done entering. Then I would add up the grades and average them up and print it. I haven't added that coding in there yet, as I am still trying to trim, get length and parse the string into a double.

I know, It would make sense to read doubles from the user, but my instructor specifically asked that we read strings then convert to doubles if and only if the user entered a length > 0 of which I already established into my code.

import java.util.*;
import java.io.*;
public class Grades {
 
	public static void main(String[] args)throws IOException {
 
   	   double validGrades = 0;
	   double d = 0;
	   double total = 0;
	   final int SIZE = 10;
	   boolean exit = false;
	   int count = 0;
	   String gradesEntered;
 
	   BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
	   String[ ] grades = new String[SIZE];
	   String[ ] trimmedGradesEntered = new String[grades.length];
 
	   System.out.println("Please enter up to 10 grades and press enter to finish.");
 
 
		while((count <= SIZE-1) && (exit == false)){
			System.out.print("Grade " + (++count) + ": ");
			gradesEntered = bf.readLine( ).trim();
 
			if(gradesEntered.length() < 1){
				exit = true;
			}
			else{
				total = total + Double.parseDouble(gradesEntered);
			}
		}
 
 
 
	}
}

Try adding some print statements to figure out where the program is going.

Start with writing down the logic/algorithm for the validation.
For example, you want the user to repeatedly enter a value until it is valid (between 0 and 100), so you would use a loop for this.

Surely you would use an integer to read in marks?

Originally Posted by Chris.Brown.SPE

Not if the grade can be 50.5

I understand that, you mentioned above about the grades being entered as Strings.