when do I write my own exception class?

Question

I have been wondering since I stepped into the murky waters of OOP and have written a couple or so of distributed libraries when it is necessary to write my own extension of the

Answer 1

The built in exception is good enough for almost every case. The only scenario that I could think of where you need another one is when there are more than one exception that can be thrown in a try and you want to do different things depending of which one is thrown. You have to distinguish two exceptions. therefore you need another one.