Visual Studio seems to be throwing an error even when changing the code

Question

This is a really weird one and kinda difficult to explain, so stay with me.

I had some pretty basic c# code which runs based on an inputted string, then that string is used put into a logger and then it does some searches etc with it.. details are somewhat unimportant.

So, it keeps throwing a "Index was outside the bounds of the array." error even though for testing purposes I am manually setting the string array right before it uses it.

args[0] = "{XXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}";
logger.Info("guid:" + args[0]); //Errors here
 _fetchxml = _myApp.getFetchXml("fileguid", args[0], new Guid(), new Guid());

I even just tried putting a line before the logger which just said var a = "a", and it gave the same error on that line, which makes me think its something with the build?

I have cleaned and rebuild the solution but with no luck, hopefully this makes sense.

Answer 1

An array is immutable (i.e. fixed size), so if the Length of the array is zero, it will throw an exception if you try to add a string and assign it to its first position (which is non-existent).

As suggested in the comments, you can simply confirm if indeed args.Length is 0 by adding an if-block:

if(args.Length > 0)
{
    args[0] = "{XXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}";
    logger.Info("guid:" + args[0]); //No more Errors here?
    _fetchxml = _myApp.getFetchXml("fileguid", args[0], new Guid(), new Guid());
}
else 
{ 
    logger.Info("guid: --no arguments found--"); 
    // or if _fetchxml is crucial:
    throw new ArgumentException("No guid given");
}

Or alternatively, if it's only for testing, you could replace the args array entirely:

args = new[] { "{XXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}" };

Or better yet, set the argument in the debug section of the project properties under 'Start options' in 'Command line arguments' (assuming these are indeed command line arguments of course).