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

Rasmus Pedersen
Rasmus Pedersen
4,093 Points
Posted by Rasmus Pedersen
Rasmus Pedersen
4,093 Points

Problems with removeValueForKey when the dictionary is a constant

The task asked me first to create a constant called currencies with the dictionary consisting of a variety of currencies, no problem.

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

After that the task was to assign the UK currencies to a constant called "ukCurrency"

let ukCurrency = currencies.removeValueForKey("UK")

I ran the code through x-code, and it all worked if I changed the constant "currencies" into a variable. But the task wont accept that approach. I have probably misunderstood something, please help :)

3 Answers

Vittorio Somaschini
Vittorio Somaschini
33,371 Points
Vittorio Somaschini
Vittorio Somaschini
33,371 Points

Hello Rasmus.

I do not think that you should call that removeValueForKey method here.

The task simply asks you to create a constant with that value, but you don't need to actually touch the dictionary.

You only need to create the variable, using the right value (assigned to the right key) in the dictionary.

So something like this:

let ukCurrency = currencies["UK"]

Where currencies["UK"] ask the compiler to look for the value with the key "UK" in that dictionary.

I hope it is clear.

Vittorio

Rasmus Pedersen
Rasmus Pedersen
4,093 Points
Rasmus Pedersen
Rasmus Pedersen
4,093 Points

Hello Vittorio

That was correct, thanks a lot :)

Looks like I made the task more complex than it was

Arman Kussainov
Arman Kussainov
4,754 Points
Arman Kussainov
Arman Kussainov
4,754 Points

You should change the type to "var".

Rasmus Pedersen
Rasmus Pedersen
4,093 Points
Rasmus Pedersen
Rasmus Pedersen
4,093 Points

Hello Arman

If I change the dictionary into - var currencies = ["US": "Dollar", "UK": "Pound", "JP": "Yen"]

I get "Bummer! You need to define a constant named 'currencies'."