title: how to get rid of compiler error: C# use of unassigned local variable?
body: <p>I have some questions why C# doesn't like the <code>coordinates[j]</code> part and what I can do about it.</p>
  
  <pre><code>string[] lines = System.IO.File.ReadAllLines(@"C:\Users\sp\Dropbox\ProjectEuler\102\p102_triangles.txt");
  string[] coordinates_str;
  double[] coordinates; //Contains the coordinates for each line A1(x,y), A2(x,y), A3(x,y)
  long ln = lines.Length;
  Console.WriteLine("Length: " + ln.ToString());
  for (int i = 0; i &lt; ln; i++)
  {
      Console.Write(i);
      Console.Write(lines[i]);
      coordinates_str = lines[i].Split(',');
      for (int j = 0; j &lt; 6; j++)
      {
          coordinates[j] = Convert.ToDouble(coordinates_str[j]);
      }
  }
  </code></pre>