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

Saeed Rehman
Saeed Rehman
455 Points
Posted by Saeed Rehman
Saeed Rehman
455 Points

Assign the value for key "UK" to a constant named ukCurrency

I am trying to assign the UK value to a constant name ukCurrency. I have typed the following and it is showing as an error. Please help.

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

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

3 Answers

Robin Malhotra
Robin Malhotra
14,883 Points
Robin Malhotra
Robin Malhotra
14,883 Points

Shouldn't it simply be

let currencies = [ "US" : "Dollar", "UK" : "Pound", "JP" : "Yen" ]
let ukCurrency = currencies["UK"]
Robin Malhotra
Robin Malhotra
14,883 Points
Robin Malhotra
Robin Malhotra
14,883 Points

Not a problem. Do consider upvoting my answer, in case other people have similar problems.

Saeed Rehman
Saeed Rehman
455 Points
Saeed Rehman
Saeed Rehman
455 Points

Hi Robin

Thanks for your support, but I have a further question. In the video Amit mentions in order to remove the value for the key, you need to type currencies.removeValueForKey("UK"), so that is why i used it. Not sure why that didn't work.

let ukCurrency = currencies.removeValueForKey("UK")

Robin Malhotra
Robin Malhotra
14,883 Points
Robin Malhotra
Robin Malhotra
14,883 Points

That's because you declared currencies with let ,thereby making it a constant. Constants are immutable, i.e, they cannot be modified. So, when you tried to modify the constant dictionary currencies, the compiler threw up an error.