Swift === with nil

Question

Why does the following not work in Swift?

if someObject === nil {
}

You have to do the test using the == operator such as

if someO         


        

Answer 1

My first instinct would be that nil is not a class instance, but a reference. So someObject cannot be an equivalent class instance to nil.

Answer 2

It works exactly like you expect:

var s: String? = nil
s === nil // true

The only caveat is that to compare to nil, your variable must able to be nil. This means that it must be an optional, denoted with a ?.

var s: String is not allowed to be nil, so would therefore always returns false when === compared to nil.