Mark list of students finding average

Question

Here when I sum the average of four subjects of student1 separately and like that when I proceed with student2 his average is being added with student1. Why is a separate average for each student not calculated? Please help.

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace ConsoleApplication3
 {
     class stud
     {
         static void Main (string[] args)
         {
             double[,] studentavg = new double[3, 4];
             double total = 0;
             int ch = 0;
             int i, j;

             while (ch == 0)
             {
                 for (i = 0; i < studentavg.GetLength(0); i++)
                 {
                     Console.WriteLine("Enter mark of student : {0}", i + 1);

                     for (j = 0; j < studentavg.GetLength(1); j++)
                     {
                         Console.WriteLine("Enter mark : {0}", j + 1);
                         studentavg[i, j] = Convert.ToDouble(Console.ReadLine());
                         total += studentavg[i, j];
                     }
                     Console.WriteLine("Average is: {0}", (total / studentavg.GetLength(1)));
                     Console.Write("Enter 1 for exit OR 0 for continue: ");
                     ch = Convert.ToInt16(Console.ReadLine());
                 }
             }
             Console.ReadLine();
         }
     }
 }

Answer 1

You are never resetting total back to 0 between students. Try adding

total = 0

after

ch = Convert.ToInt16(Console.ReadLine());

Answer 2

You placed the line "double total = 0;" outside the while loop. Don't you need to initialize it each time to zero?

You should also avoid "Convert.ToInt16" and replace it by "if (!int.TryParse(Console.ReadLine(), out ch)) { error, re-enter number } else all ok" Try to avoid predefined integer sizes. And a conversion from string to a number can always fail.