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

Lorenzo Vasquez
Lorenzo Vasquez
2,816 Points
Posted by Lorenzo Vasquez
Lorenzo Vasquez
2,816 Points

Syntax for calling dictionary value in switch

Hello,

For the challenge regarding dictionaries, for-in loop, and switch, I could not figure out why the ! operator must be placed after calling the value of the dictionary (see below):

    case "IND", "VNM": asianCapitals.append(world[key]!)

I did a Google search and saw similar examples of this exercise in order to finish the quiz. Was this explained in the previous videos? I must've missed it. Thanks in advanced for the answer.

Best, Lorenzo

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 {
    case "BEL", "LIE", "GR": europeanCapitals.append(world[key]!)
    case "IND", "VNM": asianCapitals.append(world[key]!)
    default: otherCapitals.append(world[key]!)

    }
    // End code
}

1 Answer

Dhanish Gajjar
Dhanish Gajjar
20,185 Points
Dhanish Gajjar
Dhanish Gajjar
20,185 Points

Hey Lorenzo Vasquez I think you might have misunderstood the challenge. The challenge tries to be clear by mentioning "append the value (not the key!)" It means, only append the value and not the key. Hope the example below explains it well. Best of luck.

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
}