Conventions for exceptions or error codes?

Question

Yesterday I was having a heated debate with a coworker on what would be the preferred error reporting method. Mainly we were discussing the usage of exceptions or error codes for reporting errors between application layers or modules.What rules do you use to decide if you throw exceptions or return error codes for error reporting?

Answer 1

Speaking just in my experience, it's a matter of the seriousness of the situation, the feasibility of dealing with the situation to continue and the impact if the app comes to a screeching halt.

For example, if evaluating input in an interactive mode, exception handling is probably the way to go as error information can be presented to the user to deal with it.

Conversely, processing data in a batch mode would require either halting processing when bad data encountered or bypassing input records that can't be reconciled (usually writing those to an error file for subsequent action.) There is no hard and fast rule on which to do in a given situation, as it depends on the appropriate business rules involved. It also could be a compromised between the two, bypassing error records up to a point before rejecting the entire batch.