Question

I am doing java programming practice from a website. I have to display this out put using arrays.

Enter the number of students: 3
Enter the grade for student 1: 55
Enter the grade for student 2: 108
Invalid grade, try again...
Enter the grade for student 2: 56
Enter the grade for student 3: 57
The average is 56.0

This is my source code so far. It is showing results but not working properly. It takes number of students & grade for 1st student. But then it halts, if I press any number & press enter, it asks for next grade & so on. And this way it prints average at the end. If I enter not allowed input, it catches that.
What is wrong in this code.

package array;

import java.util.Scanner;

public class GradesAverage {

    public static void main(String[] args) {

        int numStudents, sum=0;
        int[] grades;

        Scanner in = new Scanner(System.in);

        System.out.print("Enter number of students : ");
        numStudents = in.nextInt();

        grades = new int[numStudents];
      //System.out.println(grades.length);

        for (int i = 0; i < numStudents; i++) {
              System.out.print("Enter grade of student "+i+" :");
              grades[i] = Integer.parseInt(in.next());
              if(grades[i]>100 || grades[i]<0)
                {
                  System.out.println("It is not a valid number!");
                  i--;
                  continue;
                }

              //grades[i] = Integer.parseInt(in.next());
              sum+=grades[i];
        }

        System.out.print("Average grades are: "+sum/numStudents);

        in.close();
    }

}

Answer 1

Instead of using your temp variable, create a variable like this:

int grade = in.nextInt()

Then check if(grade > 100 || grade < 0) // error message

Don’t use in.next() twice, because it then asks the user for another number.