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

Posted by Aiden Mitchell
Aiden Mitchell
5,572 Points

How do I take a value from a dictionary and append it to a certain array?

I need to take the value from a dictionary and append it to a specific array using a for in loop with a switch statement inside.

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
    switch key in world [
      case "BEL": europeanCapitals.append("\(value)")
      case "LIE": europeanCapitals.append("\(value)")
      case "BGR": europeanCapitals.append("\(value)")
      case "USA": otherCapitals.append("\(value)")
      case "MEX": otherCapitals.append("\(value)")
      case "BRA": otherCapitals.append("\(value)")
      case "IND": asianCapitals.append("\(value)")
      case "VNM": asianCapitals.append("\(value)")
    ]
    // End code
}

1 Answer

Chris Sehnert
Chris Sehnert
30,857 Points
Chris Sehnert
Chris Sehnert
30,857 Points

hello,

I dropped your code into an xcode playground and with a couple of small syntax adjustments, I got it to work... ...starting inside the switch statement and working our way out.....

  • value already represents the type String....so it doesn't need to be interpolated.... append(value) ..works fine...
  • your switch statement needs a default case to ensure exhaustiveness ...i used default: break
  • next up...the body of the switch statement needs to be enclosed with {} curlys not [] brackets.....
  • lastly....you've already listed (key, value) as "for loop" temp variables ....the element you are "switching" on is the variable that represents each "case" .....in this "case" switch key {}....and you should have it!