if condition with nullable

Question

There is a lot of syntax sugar with Nullable like those:

int? parsed to Nullable

int? x = null
   if (x != null) // Parsed          


        

Answer 1

Simply put, it fails to compile because the specification says it should - an if condition requires a boolean-expression - and an expression of type Nullable isn't a boolean-expression:

A boolean-expression is an expression that yields a result of type bool; either directly or through application of operator true in certain contexts as specified in the following.

However, it's easy to work round:

if (x.GetValueOrDefault())
{
}

Or to possibly be clearer:

if (x ?? false)
{
}

The latter approach is useful as it means you can easily change the behaviour if x is null, just by changing it to x ?? true.