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iOS

Posted by Brendan Freeman
Brendan Freeman
Courses Plus Student 297 Points

What is the part that I am missing for the ukCurrency constant coding

I was just want to write the code

Stone Preston
Stone Preston
42,016 Points

can you post what you have tried so far

Brendan Freeman
Brendan Freeman
Courses Plus Student 297 Points

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

4 Answers

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

task 2 states: Assign the value for key "UK" to a constant named ukCurrency.

you can access values for keys in dictionaries by using subscript syntax which means placing the key in between brackets after the name of the dictionary:

let someValue = someDict["someKey"] // returns the value for the key of "someKey" in someDict

you need to access the value in the currencies dict with a key of "UK". 

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

let ukCurrency = currencies["UK"] // ukCurrency now has a value of "Pound"

see the Swift eBook for more information on accessing and modifying dictionaries

Brendan Freeman
PLUS
Brendan Freeman
Courses Plus Student 297 Points
Brendan Freeman
Brendan Freeman
Courses Plus Student 297 Points

ok thank you but why does adding the comment at the end allow it to work im just want to know for future reference

Stone Preston
Stone Preston
42,016 Points

comments are ignored by the compiler. they are not treated as "code" they are just there for the reader/writer of the code to reference.

Brendan Freeman
PLUS
Brendan Freeman
Courses Plus Student 297 Points
Brendan Freeman
Brendan Freeman
Courses Plus Student 297 Points

so the fact that u recalled the constant on the second part is what made the difference then right

Stone Preston
Stone Preston
42,016 Points

yes 

let ukCurrency = currencies["UK"]

basically says "give me the value from the currencies dictionary that has a key of "UK" and it returns "Pound" and that gets assigned to the constant ukCurrency

Brendan Freeman
PLUS
Brendan Freeman
Courses Plus Student 297 Points
Brendan Freeman
Brendan Freeman
Courses Plus Student 297 Points

ok I follow you thank you Im still trying to get the hang of everything

Stone Preston
Stone Preston
42,016 Points

no problem