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

Marta Bencich
Marta Bencich
9,460 Points
Posted by Marta Bencich
Marta Bencich
9,460 Points

Issue with the challenge about Dictionaries (Swift Basics).

Task 1 let currencies = ["US": "Dollar","UK": "Pound","JP": "Yen"] Task2 let ukCurrency = currencies.removeValueForKey("UK")

Task 1 results to be correct, but then on Task 2 I get an error, saying that I cannot mutate a constant (let currencies).

I tried to switch "currencies" to var in Task 1, but it won't take it.

In Xcode though it says this is correct:

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

Thanks for any help :)

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

let ukCurrency = currencies.removeValueForKey("UK")

2 Answers

Steve Hunter
Steve Hunter
57,712 Points

Hi Marta,

The challenge isn't asking you to remove the key/value pair; just to read the value from the key. So, access the currencies dictionary with the key "UK" in square brackets:

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

I hope that helps,

Steve.

Steve Hunter
Steve Hunter
57,712 Points

No problem! :smile: :+1: