Is there anything wrong with throwing exceptions in the try block?

Question

Is it a good design practice to code a try-catch block as follows? That is, use a throw in the try block and then catch it in the catch block.

try
{
  if (someCondition){

      throw new Exception("Go the the associated catch block!");

     }
}

catch(Exception ex)
{
      logError("I was thrown in the try block above");
}

Answer 1

Exceptions are for exceptional circumstances. It should not be used as control of flow logic but if there is a edge case that needs to be handled if it does come up there is nothing wrong in doing it.

I have done this myself throwing a InvalidDataException in my code if the data I am reading is not what I am expecting.

Answer 2

In general, it is not bad design, if it is the shortest writable method. But beware, that throwing an excaption usually takes approximetaly 1 ms to catch. In that matter it is a performance issue.

Answer 3

There are times when you might want to - for example, if you're using ado.net, it has a habit of throwing everything as a SqlException - you might want to catch some of these, and handle them, whilst leaving the handling of others to another level. In this case, you'd have to catch the SqlException, see if you can handle it, and rethrow it if not.

Answer 4

It depends, you should throw exception in an usual situation and is better your own exception rather than a general one.