Question

What are the best practices to consider when catching exceptions and re-throwing them? I want to make sure that the Exception object’s InnerException and stack trace are preserved. Is there a difference between the following code blocks in the way they handle this?

try {     //some code } catch (Exception ex) {     throw ex; } 

Vs:

try {     //some code } catch {     throw; } 

Answer 1

The way to preserve the stack trace is through the use of the throw; This is valid as well

try {   // something that bombs here } catch (Exception ex) {     throw; } 

throw ex; is basically like throwing an exception from that point, so the stack trace would only go to where you are issuing the throw ex; statement.

Mike is also correct, assuming the exception allows you to pass an exception (which is recommended).

Karl Seguin has a great write up on exception handling in his foundations of programming e-book as well, which is a great read.

Edit: Working link to Foundations of Programming pdf. Just search the text for ‘exception’.