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

Cyrille Turnier
Cyrille Turnier
1,715 Points
Posted by Cyrille Turnier
Cyrille Turnier
1,715 Points

What is wrong with my code?

For each case in the switch statement, I read from the dictionary like the example we used in class for the airportCodes.

Can you please let me know why the code isnt compiling?

Thanks,

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 (choice) in world {
    // Enter your code below
    switch (choice) {
      case world["BEL"]: europeanCapitals.append("Brussels")
      case world["LIE"]: europeanCapitals.append("Vaduz")
      case world["BGR"]: europeanCapitals.append("Sofia")
      case world["IND"]: asianCapitals.append("New Delhi")
      case world["VNM"]: asianCapitals.append("Hanoi")
      case world["USA"]: otherCapitals.append("Washington D.C.")
      case world["BRA"]: otherCapitals.append("Brasilia")
      case world["MEX"]: otherCapitals.append("Mexico City")

    }
 }

1 Answer

robertrinca
PLUS
robertrinca
Courses Plus Student 11,316 Points
robertrinca
robertrinca
Courses Plus Student 11,316 Points

Well, first of all your switch statement isn't exhaustive (need a default case in there).

Second, on the loop, you want to go through the key and the value. So each run through the switch statement, airportCode contains the key of the array, and the city contains the value of the array.

Third, in the case statements, just look for the strings you need, you don't need to put the array name in there.

So, to make your code go, you could use below:

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

Or if you want to make it even a little more compact, put multiple arguments on the case, so it would look like this:

for (airportCode, city) in world {
  // Enter your code below
  switch (airportCode) {
  case "BEL", "LIE", "BGR": europeanCapitals.append(city)
  case "IND", "VNM": asianCapitals.append(city)
  default: otherCapitals.append(city)
  }

Hope that helps.