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

Mark Cai
Mark Cai
1,505 Points

Code needs to use the unwrap (!) character inorder to run

Direction does not talk about using the unwrap character (!). My code only executes when using the ! character:

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 { // Enter your code below switch key { case "BEL": europeanCapitals.append(world["BEL"]!) case "LIE": europeanCapitals.append(world["LIE"]!) case "BGR": europeanCapitals.append(world["BGR"]!) case "IND": asianCapitals.append(world["IND"]!) case "VNM": asianCapitals.append(world["VNM"]!) default: otherCapitals.append(world["VNM"]!) } // End code }

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 {
    // Enter your code below

    // End code
}

1 Answer

The code is within a for/in loop that uses the temporary variables (key, value) to iterate through the dictionary - so you can use "value" to access the current value for each dictionary key. Also this way you can put multiple keys that need to take the same action within the same case:

 // Enter your code below
    switch key {
      case "BEL","LIE","BGR": europeanCapitals.append(value)
      case "IND","VNM": asianCapitals.append(value)
      default: otherCapitals.append(value)
    }