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Brilliant exception handling I found in an app i had to work on

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[-] theory@feddit.uk 6 points 1 year ago* (last edited 1 year ago)

Seen this so many times, i weep for humanity

“I’ll come back to this”

[-] bigkahuna1986@lemmy.ml 3 points 1 year ago

I'm offended that you'd put my code on the internet.

[-] sellingspams@feddit.de 1 points 1 year ago

This can't compile, can it? Only a madman commits code which doesn't compile.

[-] Shareiff@lemmy.world 1 points 1 year ago

Lol what’s wrong with this if the parent function catches it

[-] grimmi@feddit.de 1 points 1 year ago

If this is C# (and it looks like it is), this leads to you losing the original stack trace up until this point.

The correct way to do this in C# is to just throw; after you're done with whatever you wanted to do in the catch.

[-] jyte@lemmy.world 0 points 1 year ago* (last edited 1 year ago)

wait what ?

So you are saying that the following code will keep throwing e but if I used throw e; it would basically be the same except for the stack trace that would be missing the important root cause ?!

try {
} catch (WhateverException e) {
    // stuff, or nothing, or whatever
    throw; 
}
[-] TwilightKiddy@programming.dev 1 points 1 year ago

Exactly. Aside from deleting your already built stack trace, as a bonus you'll get another stack trace building call, enjoy wasted CPU cycles.

[-] ipkpjersi@lemmy.one 1 points 1 year ago

Actually, exception rethrowing is a real thing - at least in Java. You may not always want to handle the exception at the absolute lowest level, so sometimes you will instead "bubble" the exception up the callstack. This in turn can help with centralizing exception handling, separation of concerns, and making your application more modular.

It seems counter-intuitive but it's actually legit, again at least in Java. lol

[-] CannotSleep420@lemmygrad.ml 1 points 1 year ago

If your just going to let something higher on the call stack handle it, why catch it in the first place?

[-] TwilightKiddy@programming.dev 1 points 1 year ago

Rethrowing caught exception in C# is just throw;, not throw ex;. This will delete old stack trace, which is very punishable if someone debugs your code later and you're still around.

[-] bartimeo@lemmy.world 0 points 1 year ago

I am a somewhat new C# developer (2 years). Could you explain more about this?

[-] TwilightKiddy@programming.dev 1 points 1 year ago

throw ex; treats ex as a new exception, so, it starts a new stack trace for it from itself and deletes stack trace that was saved in ex.StackTrace. On the other hand, throw; takes already present exception in the scope and throws it without modifying the stack trace, preserving the original method that threw ex in the stack trace.

I feel like I wrote the same thing twice. I'm a bit bad with explaining stuff, feel free to ask more specific questions if you still don't understand the difference.

this post was submitted on 17 Jun 2023
40 points (100.0% liked)

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