Where Should Exception Messages be Stored

Question

Since I can't use Microsoft as an example for best practice since their exception messages are stored in resource files out of necessity, I am forced to ask where should exception messages be stored.

I figure it's probably one of common locations I thought of

• Default resource file
• Local constant
• Class constant
• Global exception message class
• Inline as string literals

Answer 1

Out of necessity? It's to ease localization. To localize error messages in your applications, it's a great way.

Answer 2

I may get shot (well, downvoted) for this, but why not "where you create the exception"?

throw new InvalidDataException("A wurble can't follow a flurble");

Unless you're going to internationalize the exception messages (which I suggest you don't) do you particularly need them to be constants etc? Where's the benefit?

Answer 3

If you are not going to show the exception messages to the user, then you need to keep them separate from the resource strings you do need to translate.

Either use string literals like Jon suggests or create a utility class to hold them if you have a lot of duplicate strings.

Answer 4

If your exceptions are strongly typed, you don't need to worry about messages. Messages are for presenting errors to users, and exceptions are for controlling flow in exceptional cases.

throw new InvalidOperationException("The Nacho Ordering system is not responding.");

could become

throw new SystemNotRespondingException("Nacho Ordering");

In the latter case, there's nothing to translate, and therefore no need to worry about localization.