Calculate average from .txt file

Question

I have made an exercise where I need to calculate the average per row of a .txt file. (see below)

Toa Narumi gradeA 10 8 7 4 6,5
Jean-François Le Clerk gradeB 5 4 7
Joe GradeC 10 10

I only want the numbers behind the name and grade. This is my code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Linq;
namespace RenoD_Oef_Strings
{
 class Program
 {
 static void Main(string[] args)
 {
 // Variablen
 StreamReader bestand = new StreamReader(@"F:\RenoD_Oef_Strings\Punten.txt");
 string strRow; // String used to read every row of .txt file
 double?[] dblPoints; // Double array used to store all values
 List<string> strInput = new List<string>(); // String List used to store all data from .txt
 // Code
 while ((strRow = bestand.ReadLine()) != null) // Read row per row in .txt
 {
 strInput = strRow.Split(' ').ToList(); // Puts every word in the row in to the list
 int intX = 0;
 foreach(string strX in strInput) // Calculate how many strings are in the list
 {
 intX++;
 }
 dblPoints = new double?[intX]; // Calculate the max number of elements the double array can have
 intX = 0;
 foreach(var x in strInput) // Checks if elements in the list can be converted in to a double 
 {
 try
 {
 double dblR = Convert.ToDouble(x); // If element can be converted in to a double, it will be stored in the double array
 dblPoints[intX] = dblR;
 intX++;
 }
 catch
 {
 intX++; // If element CAN NOT be converted in to a double, it will be still be stored in the double array but without any value
 }
 }
 double dblAverage = 0; // Double used to save the total average of one row
 intX = 0;
 foreach(var k in dblPoints)
 {
 if (k.HasValue) // Elements without value will be ignored
 {
 dblAverage += Convert.ToDouble(k); // All double values will be added up
 intX++; // Used to see how much double values there are to calculate average
 }
 }
 dblAverage = Math.Round(dblAverage/intX, 2); // Calculate average + round up to two decimals
 Console.WriteLine(dblAverage.ToString());
 }
 bestand.Close();
 Console.ReadKey(); 
 }
 }
}

What I have done is

• Read row per row .txt file

• Put all elements of that row in a list

• Calculate how many elements that the double array will need to store (same number of elements the list has), which I later on use to store all doubles of the list

• Check if elements in the list can be converted in to a double array; If the element can be converted in to a double, it will be stored in the double array.

If element CAN NOT be converted in to a double, it will be still be stored in the double array but without any value.

• Only calculate the average of the elements in my double array that have values.

I have tested the code, and it works without any issue.

My question is, have I taken a good approach? What would you have done to make it more efficient?

I have tried searching in other threads for solutions. I have seen simular questions, but was unable to find any exactly the same as my exercise.

• Dexter Thorn: Some tips: Dont mix german and english words. You use an object oriented language: Try to structure your code in functions. Then try to structure your code in classes. Dont mention the type of a variable in its name. This is old fashioned style. Dont write unnecessary code - use the appropriate methods of your language. If you explicitly want to implement already implemented features by yourself - use the "reinventing-the-wheel"-tag. Good luck and a lot of fun!

Answer 1

• Enclose the file reading in a using statement
• Use double.TryParse or regex to parse the numbers
• Use Linq extention method Average() to calculate average
• The size of strInput is strInput.Count, no need for a loop

Hear is a simpler code:

using (StreamReader bestand = new StreamReader(@"F:\RenoD_Oef_Strings\Punten.txt"))
{
 string strRow; // String used to read every row of .txt file
 // Code
 while ((strRow = bestand.ReadLine()) != null) // Read row per row in .txt
 {
 List<string> strInput = strRow.Split(' ').ToList(); // String List used to store all data from .txt
 List<double> dblPoints = new List<double>(); // Double list used to store all values
 foreach (var x in strInput) // Checks if elements in the list can be converted in to a double 
 {
 if (double.TryParse(x, out double result))
 {
 dblPoints.Add(result);
 }
 }
 double dblAverage = dblPoints.Average();
 Console.WriteLine(dblAverage.ToString());
 }
}
Console.ReadKey();

• Toa Narumi: Thank you for your reply! It is indeed way simpeler.
• Rick Davin: Clean and does the trick. There is theoretical edge case where a grade could be NaN, which passes the TryParse check but the average would also be a NaN. If this could be a possibility, it would need to be accounted for.