title: Data cannot be assigned
body: <p>Hello why in this function data could not be read(assigned)? 
  Error is in the line with comments(Object reference not set to an instance of an object.)</p>
  
  <pre><code>protected static int[][] GetMapFromFile(ref int size)
      {         
          using (StreamReader sr = new StreamReader(@"C:\Users\doman\OneDrive\Desktop\Antras semestras\Programavimas\Laboras1\Laboras1\Duomenys.txt"))
          {
              string skyr = " ,.;";
              size = Convert.ToInt32(sr.ReadLine());
              int[][] map = new int[size][];
              for (int i = 0; i &lt; size; i++)
              {
                  string line = sr.ReadLine();
                  string[] values = line.Split(skyr.ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
                  for (int j = 0; j &lt; values.Length; j++)
                  {
                      map[i][j] = Convert.ToInt32(values[j]); // Error here
                      Console.Write(map[i][j]);
                  }
                  Console.WriteLine();
              }
  
              return map;
          }
      }
  </code></pre>
  
  <p>My data file<br>
  5<br>
  0 1 3 4 2<br>
  1 0 4 2 6<br>
  3 4 0 7 1<br>
  4 2 7 0 7<br>
  2 6 1 7 0<br></p>