Chapter 19, Electrum Challenge Solution

Swift Programming (3rd Edition) 19. Protocols
1

I made the ProgrammingLanguage enum conform to the CaseIterable protocol, giving me access to the type’s allCases property. I iterator on the property’s collection of values and print their rawValue property.

For the gold variation of this challenge, I use the shorthand syntax $0 to access the closure’s one argument. The map(_:) instance method returns an array of the given argument’s type, and I pass the array as an argument to the print() method.

// Electrum challenge
enum ProgrammingLanguage: String, CaseIterable {
    case swift
    case objectiveC = "objective-c"
    case c
    case cpp        = "c++"
    case java
}

for language in ProgrammingLanguage.allCases {
    print(language.rawValue)
}

// Electrum gold challenge
print(ProgrammingLanguage.allCases.map({ $0.rawValue }))