Comments on: Programming with Exceptions: some thoughts. http://kristofmattei.be/2009/11/10/programming-with-exceptions-some-thoughts/ A blog on my experiences in programming, work, and life! Mon, 21 May 2012 04:23:51 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: whoami http://kristofmattei.be/2009/11/10/programming-with-exceptions-some-thoughts/comment-page-1/#comment-2199 whoami Fri, 08 Jan 2010 20:35:48 +0000 http://kristofmattei.be/2009/11/10/programming-with-exceptions-some-thoughts/#comment-2199 Hmm... When you <strong>expect</strong> that the given Id exists, and you did not find a Product for that Id: throw an exception. When it is very possible that a Product cannot be found given the (user) input, return null, and handle it elsewhere. (For instance when they (user) search on a business-key (like an invoice number for instance), it is possible that the user makes a typing error, so, I would not throw an exception in such a case, since it is not exceptional that a user makes an error). And, I think the naming convention of HawVer makes it quite self-explaining as well. Hmm…
When you expect that the given Id exists, and you did not find a Product for that Id: throw an exception.

When it is very possible that a Product cannot be found given the (user) input, return null, and handle it elsewhere.
(For instance when they (user) search on a business-key (like an invoice number for instance), it is possible that the user makes a typing error, so, I would not throw an exception in such a case, since it is not exceptional that a user makes an error).

And, I think the naming convention of HawVer makes it quite self-explaining as well.

]]> By: HawVer http://kristofmattei.be/2009/11/10/programming-with-exceptions-some-thoughts/comment-page-1/#comment-2084 HawVer Mon, 30 Nov 2009 14:40:06 +0000 http://kristofmattei.be/2009/11/10/programming-with-exceptions-some-thoughts/#comment-2084 I'd say FindProductById returns null and GetProduct throws an InvalidArgumentException. That's how most of the collection classes in .Net works. Then how to use GetProduct without breaking our execution: if (ContainsProduct(id)) Product p = GetProduct(id); I’d say FindProductById returns null and GetProduct throws an InvalidArgumentException. That’s how most of the collection classes in .Net works. Then how to use GetProduct without breaking our execution:

if (ContainsProduct(id))
Product p = GetProduct(id);

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