按键对字典进行排序

问题描述：

我想在 Swift 中对字典进行排序.我有一本像这样的字典:

I want to sort a dictionary in Swift. I have a dictionary like:

"A" => Array[]
"Z" => Array[]
"D" => Array[]

等等.我希望它像

"A" => Array[]
"D" => Array[]
"Z" => Array[]

等

我在 SO 上尝试了很多解决方案，但没有人为我工作.我正在使用 XCode6 Beta 5，其中一些给出编译器错误，一些解决方案给出异常.所以任何人都可以发布字典排序的工作副本.

I have tried many solutions on SO but no one worked for me. I am using XCode6 Beta 5 and on it some are giving compiler error and some solutions are giving exceptions. So anyone who can post the working copy of dictionary sorting.

答

let dictionary = [
    "A" : [1, 2],
    "Z" : [3, 4],
    "D" : [5, 6]
]

let sortedKeys = Array(dictionary.keys).sorted(<) // ["A", "D", "Z"]

上述代码中的排序数组仅包含键，而必须从原始字典中检索值.但是，'Dictionary' 也是 (key, value) 对的 'CollectionType'，我们可以使用全局的 'sorted' 函数来得到一个包含键和值的排序数组，如下所示:

The sorted array from the above code contains keys only, while values have to be retrieved from the original dictionary. However, 'Dictionary' is also a 'CollectionType' of (key, value) pairs and we can use the global 'sorted' function to get a sorted array containg both keys and values, like this:

let sortedKeysAndValues = sorted(dictionary) { $0.0 < $1.0 }
println(sortedKeysAndValues) // [(A, [1, 2]), (D, [5, 6]), (Z, [3, 4])]

目前更喜欢每月更改的 Swift 语法

The monthly changing Swift syntax currently prefers

let sortedKeys = Array(dictionary.keys).sort(<) // ["A", "D", "Z"]

不推荐使用全局 sorted.

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