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

Posted by shanekillian
shanekillian
Courses Plus Student 906 Points

note: change 'let' to 'var' to make it mutable

Should this really work?

I'm trying it in a playground too and it is complaining that I have the constant currencies while trying to assign constant ukcurrency a value.

The error in playground is:

"note: change 'let' to 'var' to make it mutable"

On tem treehouse, is complains that code cannot be compiled but doesn't make sense to me when I check the errors.

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

let ukCurrency = currencies.removeValueForKey("UK")
Kieran Black
Kieran Black
9,139 Points

Hi Shane,

I do not believe this should work as currencies is set to be a constant and therefore once set cannot be altered (constants are immutable), should you need to change it then changing it from a constant to a variable should work:

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

let ukCurrency = currencies.removeValueForKey("UK")

Hope that makes sense. Happy coding :octopus:

1 Answer

shanekillian
PLUS
shanekillian
Courses Plus Student 906 Points
shanekillian
shanekillian
Courses Plus Student 906 Points

I agree with you Kieran but that doesn't seem to be the case here. Your code also gets rejected because it wants to have dict as constant.

The question is :

"Create a constant named ukCurrency. Assign the value from the currencies dictionary. Use the key of "UK" to access the value."

But the previous questions was: "Let's create a dictionary that contains the currencies of the various countries along with their country codes. The country code will be the key and the currency the value. Using the following key-value pairs: US : Dollar, UK : Pound, JP : Yen assign them to a constant named currencies."

I don't believe I can work past this?