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Quite often, in programming we get situations where null checks show up in particularly large numbers. I'm talking about things like:
if (doc != null) { if (doc.Element != null) { ... and so on } else throw new Exception("Element cannot be null"); } else { throw new Exception("document cannot be null"); } Basically, the whole thing turns into an unreadable nightmare, so I'm wondering: is there an easier way to describe what I'm trying to do above? (In addition to null checks, I get things like string.IsNullOrEmpty from time to time.)
Accepted answer: I accepted the answer that has this link because the approach described is innovative, and is precisely what I want. Thanks Shawn!
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It is a good idea to check for null explicitly because: You can catch the error earlier. You can provide a more descriptive error message.
A null indicates that a variable doesn't point to any object and holds no value. You can use a basic 'if' statement to check a null in a piece of code. Null is commonly used to denote or verify the non-existence of something.
If you have implemented layering in your project, good place to do null checks are the layers that receives data externally. Like for example: the controllers, because it receives data from the user... or the gateways because it receives data from repositories.
Check out this article: A fluent approach to C# parameter validation
It's written by one of the Paint.NET Developers. He uses extension methods to simplify and clean up null checking code.
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Push them forward to the beginning of the function, and keep them out of the part of the code that does the work. Like this:
if (doc == null) throw new ArgumentNullException("doc"); if (doc.Element == null) throw new ArgumentException("Element cannot be null"); AndSoOn(); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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