Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Swift Collections and Control Flow Dictionaries in Swift Modifying a Dictionary

Emanuele Gorga
Emanuele Gorga
5,020 Points

update dictionary

Hello guys, I have been trying in many different ways, trying to restart XCODE too but just doesn't want to work out. When I try to use updateValue in order to update a value in the dictionary (but because doesn't find anything it just add a new value), my Xcode is giving me an error:

var airportCodes: [String: String] = ["LGA": "La Guardia", "LHR": "Heathrow", "CDG": "Charles de Gaulle", "HKG": "Hong Kong International", "DXB": "Dubai International"]

airportCodes.updateValue("Dublin Airport", forKey: DUB)

Playground execution failed:

error: SwiftBasics.playground:72:52: error: use of unresolved identifier 'DUB' airportCodes.updateValue("Dublin Airport", forKey: DUB) ^~~

Do you know how to help me out? THANK YOU

1 Answer

Jeff McDivitt
Jeff McDivitt
23,970 Points

You need the quotations around DUB because it is a string

var airportCodes: [String: String] = ["LGA": "La Guardia", "LHR": "Heathrow", "CDG": "Charles de Gaulle", "HKG": "Hong Kong International", "DXB": "Dubai International"]

airportCodes.updateValue("Dublin Airport", forKey: "DUB")
Emanuele Gorga
Emanuele Gorga
5,020 Points

yeah perfect now it works :) thank you!