Performance Cost Of 'try' in C#

Question

I know that exceptions have a performance penalty, and that it's generally more efficient to try and avoid exceptions than to drop a big try/catch around everything -- but what about the try block itself? What's the cost of merely declaring a try/catch, even if it never throws an exception?

Answer 1

The performance cost of try is very small. The major cost of exception handling is getting the stack trace and other metadata, and that's a cost that's not paid until you actually have to throw an exception.

But this will vary by language and implementation. Why not write a simple loop in C# and time it yourself?

Answer 2

Actually, a couple months ago I was creating an ASP.NET web app, and I accidentally wrapped a try / catch block with a very long loop. Even though the loop wasn't generating every exceptions, it was taking too much time to finish. When I went back and saw the try / catch wrapped by the loop, I did it the other way around, I wrapped the loop IN the try / catch block. Performance improved a LOT. You can try this on your own: do something like

int total;

DateTime startTime = DateTime.Now;

for(int i = 0; i < 20000; i++)
{
try
{
total += i;
}
catch
{
// nothing to catch;
}
}

Console.Write((DateTime.Now - startTime).ToString());

And then take out the try / catch block. You'll see a big difference!