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

riyajain23
riyajain23
2,348 Points
Posted by riyajain23
riyajain23
2,348 Points

Retrieving Info From Dictionaries

I was supposed to create a constant, called "currencies", and then assign the following values to it: (US: Dollar, UK: Pound, JP: Yen). This worked, but then it asked me to retrieve a value. I was supposed to retrieve the value for UK currency (Pound), and assign it to the constant ukCurrency. This is where the code was apparently incorrect. The error is in the retrieving line. What's the error, and how can I solve it?

Andrew Rodko
Andrew Rodko
27,881 Points
Andrew Rodko
Andrew Rodko
27,881 Points

Hi, could you show me the code you have for this so far?

riyajain23
riyajain23
2,348 Points
riyajain23
riyajain23
2,348 Points

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

let ukCurrency = currencies.removeValueForKey("UK")

2 Answers

Andrew Rodko
Andrew Rodko
27,881 Points
Andrew Rodko
Andrew Rodko
27,881 Points

The issue is that you're attempting to remove the value from the dictionary, and the dictionary is defined as a constant. This would work if you define currencies with var instead of let to make it mutable, but here's the best answer for just retrieving the value: let ukCurrency = currencies["UK"]

riyajain23
riyajain23
2,348 Points
riyajain23
riyajain23
2,348 Points

Okay. Thanks so much!

swiftfun
swiftfun
4,039 Points
swiftfun
swiftfun
4,039 Points

Hello Vipin,

In this objective you need to create a dictionary using the specified KV (key-value pairs).

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

Once the dictionary is ready you are asked to retrieve "UK" currency. You can retrieve a value by simply calling it's key:

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

let ukCurrency = currencies["UK"]