Question

I have searched for an answer to my question but not been able to find one. Apologies if the answer is there and I am duplicating!

I keep seeing try/catch code such as…..

try
{
    //Do whatever
}
catch (Exception ex)
{
    MessageBox.Show("Oops, something went wrong!");
}

Which will result in a warning ex is never used.

So my question is… Although ex is never used is there any benefit in the declaration? I was told that maybe it adds detail to the stack trace? Sometimes I see catch(Exception) which stops the warning but what benefits does this bring, if any? If I was to write this and not use the exception in any way I wouldn’t declare ex…

try
{
    //Do whatever
}
catch
{
    MessageBox.Show("Oops, something went wrong!");
}

Not a big problem but it would be good to know for sure!

Thanks

Fred

Answer 1

You can use the following pattern, still declaring the specific exception type, without a variable, to ensure Structured Exception Handling (SEH) is still happening:

try
{
    //Do whatever
}
catch (IOException)
{
    MessageBox.Show("Oops, something went wrong in the IO!");
}
catch (Exception)
{
    MessageBox.Show("Oops, something went wrong!");
}

This is not a practice I would normally use, as I would probably log the exception details if not rethrowing it.