oscilatingcretin oscilatingcretin - 2 months ago 6
C# Question

Is it possible for null-conditionals to not return nullable value types while checking conditions?

When assigning a value from a null-conditional, it makes sense to return a nullable value type. Otherwise, if the object is null, the null-conditional would return the value type's default and you don't want that. Therefore, this is good:

bool? IsTerminated = Employee?.IsTerminated;


However, why does it return a nullable type if I am just checking a condition? You would think that the compiler could figure this out just fine:

if (Employee?.IsTerminated) { /*do something here*/ }


After all, it's just compiling down to this, right?

if (Employee != null && Employee.IsTerminated) { /*do something here*/ }


In order to get it to work, I have to do this:

if ((Employee?.IsTerminated).GetValueOrDefault()) { /*do something here*/ }


Between the extra code and having to wrap the expression in parens, the whole purpose of the null-conditional's short-hand syntax appears to be defeated. Is this the proper way to handle a null-conditional return value or is there another way that doesn't involve accounting for a nullable return value?

Answer

If A?.B contains B of a reference type, then you'll get a return of type B. Otherwise, if B is a value type, the return type is a nullable wrapping around type B. So, that's a short answer to your question.

With that being said, in your case, since you're getting back a bool, it's understandable that it'll be wrapped as bool?. Knowing that, you should simply work with it as you would normally would with bool?. One way is to simply do an equality comparison to a desired value of bool.

For example:

if (Employee?.IsTerminated == true) { }

It's a bit shorter and easier to read than:

if ((Employee?.IsTerminated).GetValueOrDefault()) {  }

The example comparison works, because null will never equal to a bool.

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