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

Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points
Posted by Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points

Hello It came to my attention that this exercise is broken, as you cannot removeValueForKey from a constant.

// it has to be:

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

let ukCurrency = currencies.removeValueForKey("UK")

dictionaries.swift 
var currencies = [  "US": "Dollar",
                    "UK": "Pound",
                    "JP": "Yen"]

5 Answers

Steve Hunter
Steve Hunter
57,712 Points

Hi,

Apologies for my previous answer - I hadn't read the code challenge!!

I don't think you're removing anything from the constant called currencies. You create the dictionary, then assign the value of currencies["UK"] to a constant called ukCurrency. There's no removing of anything from the immutable dictionary.

Steve.

Steve Hunter
Steve Hunter
57,712 Points 
let currencies = ["US" : "Dollar", "UK" : "Pound", "JP" : "Yen"]
let ukCurrency = currencies["UK"]
Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points
Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points

Yes i am aware of that, I just found a solution to this problem. Instead of removing value which can't be done when dictionary is a constant. You can add value by doing this:

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

Then the question can be completed :) But thanks for your help

Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points
Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points

Thanks for your quick reply :)

Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Exactly, yes. The question didn't want to remove anything from the dictionary; just assign a value from it to a constant.

Hope you're enjoying the course!

Steve.

Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points
Andriy Yezerskiy
Andriy Yezerskiy
1,808 Points

Thanks a lot for your help :) I sure will.

Andriy