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iOS Swift 2.0 Collections and Control Flow Control Flow With Conditional Statements Working with Switch Statements

Posted by Sam Murphy
Sam Murphy
10,469 Points

How do i correctly append a key in a switch?

here is the code challenge: Here we have a dictionary of type [String: String] 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've already set up the for in loop for you so jump right in!

switch.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 europeanCapitals {
    case "BEL": europeanCapitals.append(key, "BEL")
    }
    switch asianCapitals {
    }
    switch otherCapitals {
    }
    // End code
}
Ben Masel
Ben Masel
2,004 Points
Ben Masel
Ben Masel
2,004 Points

I'll answer in a minute!

Ben Masel
Ben Masel
2,004 Points
Ben Masel
Ben Masel
2,004 Points

LOL! I didn't notice this was to teach people!

1 Answer

Ben Masel
Ben Masel
2,004 Points
Ben Masel
Ben Masel
2,004 Points
switch.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 {

    case "BEL", "LIE", "BGR":
        europeanCapitals.append(value)

    case "IND","VNM":
        asianCapitals.append(value)

    default:
        otherCapitals.append(value)
    }

    // End code

}