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

Posted by David Velez
David Velez
Courses Plus Student 326 Points

Help with constants

First I'm asked to create a constant....then I'm asked to create another constant and assign it a value from the first constant?

Not sure how to go about this?

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

let ukCurrency = ["UK"]

1 Answer

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hey David,

You're actually super close. Right now, you're just assigning ukCurrency the literal value ["UK"] (a one-item array of strings). Instead, you want to use the key ["UK"] to assign the value from the dictionary, currencies. You just need to index into the dictionary like this: dictionary["key"]

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

let ukCurrency = currencies["UK"]

This makes ukCurrency hold the string "Pound". Make sense?

David Velez
David Velez
Courses Plus Student 326 Points

Aha! Okay now i get it :-) Thanks Greg!