Swift 2 - 将数组分成带有从 A 到 Z 的键的字典

例如，我有一个数组["Apple", "Banana", "Blueberry", "Eggplant"]我想将其转换为字典，如下所示：

[
    "A" : ["Apple"],
    "B" : ["Banana", "Blueberry"],
    "C" : [],
    "D" : [],
    "E" : ["Eggplant"]
]

我在 Xcode 7 beta 4 上使用 Swift 2。谢谢！

仅使用 Swift 2 对象和方法，并为字母表中的每个字母指定一个键：

let alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".characters.map({ String($0) })

let words = ["Apple", "Banana", "Blueberry", "Eggplant"]

var result = [String:[String]]()

for letter in alphabet {
    result[letter] = []
    let matches = words.filter({ $0.hasPrefix(letter) })
    if !matches.isEmpty {
        for word in matches {
            result[letter]?.append(word)
        }
    }
}

print(result)