🅰Б
let data = ["Anton", "Anna", "John", "Caesar"]
var letters: [Character]
letters = data.map { name in
return name[name.startIndex]
}
letters = letters.sorted()
letters = letters.reduce([], { (list, name) -> [Character] in
if !list.contains(name) {
return list + [name]
}
return list
})
// Build contacts array:
var contacts = [Character: [String]]()
for entry in data {
if contacts[entry[entry.startIndex]] == nil {
contacts[entry[entry.startIndex]] = [String]()
}
contacts[entry[entry.startIndex]]!.append(entry)
}
for (letter, list) in contacts {
contacts[letter] = list.sorted()
}