Validating a Range of Inputs Within a WHILE Loop

Question

Could someone explain to me how I could put a conditional of grade can only be 0 or greater or 100 or less. I've tried the statement inside the while loop, but then the average doesn't come out correct. I've put it outside the loop, but that doesn't seem to work either.

 while (!gradeInput.equals(SENTINEL)) {

         try {
            int grade = Integer.parseInt(gradeInput);


            sum += grade;
            count++;

         }
         catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(null,"Error! only numeric values.");
         }


         gradeInput = JOptionPane.showInputDialog("Enter exam grade (or -1 to end the program):");
      }

for JOptionPane validation refer to stackoverflow.com/questions/3544521/… — Sheetal Mohan Sharma
– Sheetal Mohan Sharma, Commented Jun 11, 2015 at 14:00

ozborn · Accepted Answer · 2015-06-11 14:10:18Z

1

The comment from Sharma is probably cleaner, but this should work too:

gradeInput calculation should be at the beginning of the loop - not the end.

Then put your validation inside the loop like this (only summing and counting if the input is valid)

if(grade>0 && grade <100) {
        sum += grade;
        count++;
}

Then calculate the average outside the loop with a sum/count

answered Jun 11, 2015 at 14:10

ozborn

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Mohammed Sohail Ebrahim · Accepted Answer · 2015-06-11 14:40:43Z

0

 while (!gradeInput.equals(SENTINEL)) {

     try {



        int grade = Integer.parseInt(gradeInput);
if(grade==0 || grade<=100){

        sum += grade;
        count++;
}
     }
     catch (NumberFormatException e) {
        JOptionPane.showMessageDialog(null,"Error! only numeric values.");
     }


     gradeInput = JOptionPane.showInputDialog("Enter exam grade (or -1 to end the program):");
  }

answered Jun 11, 2015 at 14:40

Mohammed Sohail Ebrahim

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Comments

Arun Kumar · Accepted Answer · 2015-06-11 14:46:02Z

0

Try this

while (!gradeInput.equals(SENTINEL)) {
         try {
            int grade = Integer.parseInt(gradeInput);
            if(grade>=0 && grade<=100){
               sum += grade;
               count++;
            }
         }
         catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(null,"Error! only numeric values.");
         }
         gradeInput = JOptionPane.showInputDialog("Enter exam grade (or -1 to end the program):");
      }

answered Jun 11, 2015 at 14:46

Arun Kumar

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