Updated for Xcode 15
Now that you understand a little about optionals, it’s time to pause for a few minutes and try a small coding challenge so you can see how much you’ve remembered.
Your challenge is this: write a function that accepts an optional array of integers, and returns one randomly. If the array is missing or empty, return a random number in the range 1 through 100.
If that sounds easy, it’s because I haven’t explained the catch yet: I want you to write your function in a single line of code. No, that doesn’t mean you should just write lots of code then remove all the line breaks – you should be able to write this whole thing in one line of code.
I’ll provide some hints in a moment, but first I recommend you go ahead and try it yourself.
Hacking with Swift+ subscribers can get a complete video solution for this checkpoint here: Solution to Checkpoint 9. If you don’t already subscribe, you can start a free trial today.
Still here? Okay, here are some hints:
[Int]?
– an array of integers that might be there, or might be nil
.Int
.randomElement()
on the optional array, which will in turn return another optional.TAKE YOUR SKILLS TO THE NEXT LEVEL If you like Hacking with Swift, you'll love Hacking with Swift+ – it's my premium service where you can learn advanced Swift and SwiftUI, functional programming, algorithms, and more. Plus it comes with stacks of benefits, including monthly live streams, downloadable projects, a 20% discount on all books, and free gifts!
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