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iOS Swift Enums and Structs Enums Review Enums

Conor Carey
Conor Carey
3,775 Points
Posted by Conor Carey
Conor Carey
3,775 Points

I don't understand why the datatype answer is an optional rather than a day

One of the review enum questions in the swift training course asks for the datatype of a piece of data (I don't remember the specifics), but I do remember being confused when the answer said it was an optional rather than a day. Can someone please clarify this?

1 Answer

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Conor!

You should probably review this video from a couple lessons ago on enums and raw values.

In the quiz, the Day is being initialized with a raw value. Something like...

let today = Day(rawValue: 2)

Because Swift can't be certain you'll provide a valid raw value (we could have written rawValue: 238), when you initialize an instance of Day in this way, the datatype is optional. You can use if let, or the ! operator to get around this.

Hope this helps! As I said, I recommend watching the video again, since Amit goes into more detail, and you can follow along in Xcode.

-Greg