The as Operator
You might wonder why I made all that fuss about the underlying implementation of the
is operator. Well, as you’ve seen, the
is operator actually performs a cast underneath the covers and checks the result against null to determine whether the cast succeeded. Contrast this with the behavior of the cast expression that throws an
InvalidCastException in case of a failed cast. Clearly, both cast mechanisms are useful.
This brings us to the
as operator, which is the gentle equivalent to the cast expression: Instead of throwing an exception on failure to cast, it simply returns null. In the previous example where we dispatched types using the
is operator, we actually did things rather inefficiently. First we carried out a type check: ...