Swift_数组排序sorted

[使用]：返回排序后的元素序列。
你可以通过调用这个方法对符合“Comparable”协议的任何元素序列进行排序。

1、默认元素序列按【升序】排序。
/// Strings in Swift conform to the `Comparable` protocol
///     let students: Set = ["Kofi", "Abena", "Peter", "Kweku", "Akosua"]
///     let sortedStudents = students.sorted()
///     print(sortedStudents)
///     // Prints "["Abena", "Akosua", "Kofi", "Kweku", "Peter"]"

2、修改元素序列按【降序】排序。
///     let descendingStudents = students.sorted(by: >)
///     print(descendingStudents)
///     // Prints "["Peter", "Kweku", "Kofi", "Akosua", "Abena"]"