Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift Collections and Control Flow Control Flow With Conditional Statements Working With Switch Statements

I need help! PLS! ; )

I am not quite sure what I need to fix. Here is the question I am stuck on: In the editor we have a dictionary that contains a three letter country code as a key and that country's capital city as the associated value.

We also have three empty arrays, europeanCapitals, asianCapitals, and otherCapitals. The goal is to iterate through the dictionary and end up with just the names of the capital cities in the relevant array.

For example, after you execute the code you write, europeanCapitals will have the values ["Vaduz", "Brussels", "Sofia"] (not necessarily in that order).

To do this you're going to use a switch statement and switch on the key. For cases where the key is a European country, append the value (not the key!) to the europeanCapitals array. For keys that are Asian countries, append the value to asianCapitals and finally for the default case, append the values to otherCapitals.

I need any help I can get! PLS HELP ME! ; )

operators.swift
var europeanCapitals: [String] = []
var asianCapitals: [String] = []
var otherCapitals: [String] = []

let world = [
  "BEL": "Brussels", 
  "LIE": "Vaduz", 
  "BGR": "Sofia", 
  "USA": "Washington D.C.", 
  "MEX": "Mexico City", 
  "BRA": "Brasilia", 
  "IND": "New Delhi", 
  "VNM": "Hanoi"]

for (key, value) in world {
switch world
case "BEL": print("Brussels")
case "LIE": print("Vaduz")
case "BGR": print("Sofia")
case "USA": print("Washington D.C.")
case "MEX": print("Mexico City")
case "BRA": print("Brasilia")
case "IND": print("New Delhi")
case "VNM": print("Hanoi")
default: print("otherCapitals")
    }
}

1 Answer

Christian Mangeng
Christian Mangeng
15,970 Points

Hi Joshua,

You need to iterate over the key, value pairs in order to solve this task (you did that correctly so far)

for (key, value) in world {
    switch key {
    }
}

You compare each key of the dictionary (so use "switch key", instead of "switch world") with the switch cases. A case may look like that.

case "BEL": europeanCapitals.append(value)

You append the value of the matched key to the correct list. I think you can make the rest on your own.

Good luck

Where do I put the: case "BEL": europeanCapitals.append(value)?

This is what I am doing and it is not working. var europeanCapitals: [String] = [] var asianCapitals: [String] = [] var otherCapitals: [String] = []

let world = [ "BEL": "Brussels", "LIE": "Vaduz", "BGR": "Sofia", "USA": "Washington D.C.", "MEX": "Mexico City", "BRA": "Brasilia", "IND": "New Delhi", "VNM": "Hanoi"]

for (key, value) in world { switch key { } case "BEL": europeanCapitals.append(value) }

Oh ok never mind all those questions. Ive got it now.