Question

I have the following code :

 public List<IAction> Dispatch(string[] arg)
   {
       int time=0;
       int i = 0;
       int j = 0;
       List<IAction> t = new List<IAction>(10);
       do
       {
           if (arg[j][0] == '/') // I get index out of bounds here
           {
               Options opt = new Options();                   

               time = opt.Option(arg[j]);
               j++;
           }
           else
           {
               if (int.Parse(arg[j]) >= 0 && int.Parse(arg[j]) <= 20)
               {
                   t.Add(new ComputeParam(int.Parse(arg[j])));
                   i++;
                   j++;                      
               }
           }

       } while (i != arg.Length);
       for (int z = 0; z < t.Count; z++)
       {
           ((ComputeParam)t[z]).Time = time;
       }
       return t;
   }

Why does the error happen… I just pass the arguments and if they are numbers I add them to a list, if not I set an option and move on. What is the problem here?

Edit : I pass 2 /t:Med 2 3
those are the arguments. I aleready checked it arg[1] (in this case) is null, but it’s not.

Answer 1

I see a couple of possible issues here:

1. If arg[] is empty, you will get the exception
2. If arg[j] is an empty string, you will get the exception
3. If you have any options, you will get the exception on a later execution of the loop, because j is being incremented, but i is not.

I think this will fix it:

public List<IAction> Dispatch(string[] arg)
{
   int time=0;
   List<IAction> t = new List<IAction>(10);
   for (int j = 0; j < arg.Length; j++)
   {
       if (!String.IsNullOrEmpty(arg[j]) && arg[j][0] == '/')
       {
           Options opt = new Options();                   

           time = opt.Option(arg[j]);
       }
       else
       {
           if (int.Parse(arg[j]) >= 0 && int.Parse(arg[j]) <= 20)
           {
               t.Add(new ComputeParam(int.Parse(arg[j])));
               // Don't need to increment i                
           }
       }

   }
   for (int z = 0; z < t.Count; z++)
   {
       ((ComputeParam)t[z]).Time = time;
   }
   return t;
}