Null parameter checking in C#

Question

In C#, are there any good reasons (other than a better error message) for adding parameter null checks to every function where null is not a valid value? Obviously, the code tha

Answer 1

You might want to take a look at Code Contracts if you need a nicer way to make sure you do not get any null objects as a parameter.

Answer 2

It saves some debugging, when you hit that exception.

The ArgumentNullException states explicitly that it was "s" that was null.

If you don't have that check and let the code blow up, you get a NullReferenceException from some unidentified line in that method. In a release build you don't get line numbers!

Answer 3

I've been using this for a year now:

_ = s ?? throw new ArgumentNullException(nameof(s));

It's a oneliner, and the discard (_) means there's no unnecessary allocation.