Question

I am trying to get to grips with C# having not coded for many years and my previous experience being in ANSI C.

I have read a number of books and searched online but one aspect is evading me and I am hoping someone here can help.

In the past I would declare a function and if there was a possibility of something not happening within the function (i.e. file not found etc.) declare the return to be an integer. I would then return 0 if all was well and a value if not. The value would correspond to where the function failed to execute fully and I could branch accordingly from where I called it.

if(function1())
  {
   // all my error stuff, maybe a switch/case etc.
  }

All the examples I have found in C# seem to avoid this technique and I was hoping to get some understanding here.

Thanks in anticipation.

(I know I am a fossil). 🙂

Answer 1

If you want to follow that pattern of checking return value instead of managing errors, you better use enumarations than plain numbers.

For example:

public enum ResultType
{
    Error = 0,
    Success,
    Waiting
}

public ResultType function()
{
    if (still_waiting)
        return ResultType.Waiting;

    if (error_has_occured)
        return ResultType.Error;

    return ResultType.Success;
}

public void Main()
{
    ResultType result = function();
    switch (result)
    {
        case ResultType.Success:
            MessageBox.Show("all is good");
            break;
        case ResultType.Waiting:
            MessageBox.Show("still waiting...");
            break;
        case ResultType.Error:
            MessageBox.Show("error has occurred");
            break;
    }
}

Behind the scenes, it’s still using numbers but you put some meaning to each number.