ios - 按原始顺序获取数组中字典的键

Question

假设我有一本字典

let dict = [
    "Joe":"D.",
    "Ben":"K.",
    "Kyle":"R.",
    "Matt":"L."
]

如果我想要这个字典的键数组，我会这样做:

let keys = Array(dict.keys)

但这以看似随机的顺序打印:

["Ben", "Joe", "Matt", "Kyle"]

有没有办法得到一个与原始字典具有相同顺序的键数组？

即

["Joe", "Ben", "Kyle", "Matt"]

Answer 1

字典没有顺序。当我们向字典添加新元素时，我们现在没有顺序。您可以使用元组数组

        let array = [("Joe", "D."), ("Ben", "K."), ("Kyle", "R.")]
        print(array)
//        [("Joe", "D."), ("Ben", "K."), ("Kyle", "R.")]
        let keys = array.map { $0.0 }
        print(keys)
//        ["Joe", "Ben", "Kyle"]