Question

I found this question in an old question in your website so i thought i can do it but I think I was mistaken 🙂

the old post was here

I’m new at the jagged array thing so did the following code

StreamReader rows = new StreamReader('c:\\practice.txt');             string line;             int i;             i=1;             while ((line = rows.ReadLine()) != null)             {                 String[][]rows = new String [i][]; ;                 rows = rows.ReadLine();                 String[][] rows = new string[S.Length][];                 i++;             }             for (int i; i < S.Length; i++)             {                  row[i] = S[I].Split(',');              }              int totalCounter = 0, totalSum = 0;             // etc             foreach(string[] row in rows)             {                     int m1 = int.Parse(row[3]);                 totalCounter++;                 totalSum += m1;                 switch(row[2])                 {                             case 'male':                     maleCount++;                                 maleSum += m1;                                     break;                             case 'female':                                     femaleCount++;                                     femaleSum += m1;                                     break;                     }             } 

I know i did major mistakes but at east i tried can any one help me to make it a workin code

Answer 1

You seem to be double-reading the lines, or maybe you’ve mixed up rows and cells – this bit in particular looks really odd:

        while ((line = rows.ReadLine()) != null)         {             String[][]rows = new String [i][]; ;             rows = rows.ReadLine();             String[][] rows = new string[S.Length][];             i++;         } 

i.e. re-declaring rows, two calls to ReadLine per loop, etc. I suspect you mean string.Split? Either way, either use File.ReadAllLines, or look at some of the options presented yesterday. If you are desperate to use arrays, the core might look something like:

using System; using System.IO; static class Program {     static void Main()     {         string[] lines = File.ReadAllLines('foo.txt');         string[][] grid = new string[lines.Length][];         for (int i = 0; i < lines.Length; i++)         {             grid[i] = lines[i].Split(',');         }          int totalCount = 0, maleCount = 0, femaleCount = 0,             m1Total = 0, m2Total = 0, m3Total = 0,             m1MaleTotal = 0, m1FemaleTotal = 0;         foreach (string[] line in grid)         {             totalCount++;             int m1 = int.Parse(line[3]),                 m2 = int.Parse(line[4]),                 m3 = int.Parse(line[5]);             m1Total += m1;             m2Total += m2;             m3Total += m3;             switch (line[1].Trim())             {                 case 'male':                     maleCount++;                     m1MaleTotal += m1;                     break;                 case 'female':                     femaleCount++;                     m1FemaleTotal += m1;                     break;             }         }         Console.WriteLine('Rows: ' + totalCount);         Console.WriteLine('Total m1: ' + m1Total);         Console.WriteLine('Average m1: ' + ((double)m1Total)/totalCount);         Console.WriteLine('Male Average m1: ' + ((double)m1MaleTotal) / maleCount);         Console.WriteLine('Female Average m1: ' + ((double)m1FemaleTotal) / femaleCount);     } } 

Again – I cannot stress enough how much you should be doing this with LINQ instead of manual looping…