Set NSNull() if the string is nil

Question

When a user does facebook login in my app, some of the expected value such as dateOfBirth, email can be nil. I want to set the value of self.fbResponse.email to NSNull(), if it is nil. So that I can post the parameters to server.

        let parameter:[String:AnyObject] =
            [
                "facebookId":self.fbResponse.fbID!,
                "fbToken":"randomToken",
                "email" : self.fbResponse.email!,
                "dateOfBirth": self.fbResponse.dob,
                "gender" : self.fbResponse.gender!,
                "info": self.fbResponse.aboutMe!,
                "fullName":self.fbResponse.fullName!,
                "profileImageUrl":self.fbResponse.pictureURL!
                "location": location
        ]

Couldn't you just omit the key. if it's `nil`, or send empty string? — vadian, May 01 '16 at 09:42

score 7 · Accepted Answer · answered May 01 '16 at 09:45

You can use the ?? operator for that:

"email" : self.fbResponse.email ?? NSNull()

It assigns the unwrapped value of self.fbResponse.email if that is not nil, and assigns NSNull() otherwise.

The operator "short circuits", which means the right-hand side is not evaluated unless it really needs to because the left-hand side is nil.

Set NSNull() if the string is nil

1 Answers1