Updated for Xcode 14.2
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.SPONSORED In-app subscriptions are a pain to implement, hard to test, and full of edge cases. RevenueCat makes it straightforward and reliable so you can get back to building your app. Oh, and it's free if your app makes less than $10k/mo.
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