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

David Petrin
David Petrin
3,384 Points
Posted by David Petrin
David Petrin
3,384 Points

What is wrong with my second line of code?

What is wrong with my second line of code?

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

2 Answers

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

Hi David,

Because you used let to declare your dictionary, it's a constant, and you can't use removeValueForKey on it. Change let currencies to var currencies and it would work. However, there's no reason to use removeValueForKey in this case - you don't need to change the dictionary. Instead, just index into it and grab the value for "UK".

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

Best,

Greg

David Petrin
David Petrin
3,384 Points
David Petrin
David Petrin
3,384 Points

Thanks for the help Greg!