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iOS Swift Basics (retired) Collections What is a Dictionary?

The challenge for the Dictionaries lesson in the Collections stage (4) has you define a constant called currencies

...and then asks you to modify it. There's no way to get through it, it should be a variable instead.

3 Answers

Stone Preston
Stone Preston
42,016 Points

the task states: Assign the value for key "UK" to a constant named ukCurrency.

you arent modifying the dictionary at all, you are just accessing one of the values it stores using a key, and assigning that value to another constant

let currencies = ["US":"Dollar", "UK":"Pound", "JP": "Yen"]
let ukCurrency = currencies["UK"] //= the value of currencies["UK"] which is "Pound"

Thanks Stone. I thought they were asking me to do something like this:

let currencies = ["US":"Dollar", "UK":"Pound", "JP": "Yen"]
let ukCurrency = "Pound"
currencies["UK"] = ukCurrency

...which obviously produced an error.

Alamuddin Bakhit
Alamuddin Bakhit
1,355 Points

I had the same confusion too, thanks stone for the answer! :)