Swift standard library provide a method called sort ( _: ) ,which sort an array of a known type,base on the output of a sorting closure that you provide.Once it completes the sorting process,the sort ( _: ) method returns a new array of the same size and type as old one,with its elements in the correct sorted order.the original array isn't modified by the sort ( _: ) method.
The closure expression example below use sort ( _: ) to sort a array of string type in reverse alphabetical order.Here is the initial array to be sorted:
let names = ["Chris","Alex","Ewa","Barry","Daniella"]
swift 标准库提供 sort ( _: ) 排序方法，它可以给一个 已知类型 的array排序。排序规则基于你写的 排序 闭包。当排序完成时，sort ( _: ) 方法返回一个新数组，新数组与原来的数组有相同的大小和类型。但数组中元素排序变了。原数组不会被sort ( _: ) 方法修改。
下面的闭包表达式使用sort ( _: )方法给 一个string类型的 数组 按 字母逆序 排序。
let names = ["Chris","Alex","Ewa","Barry","Daniella"]
翻译就先到这，来总结一下闭包。举个栗子
{ ( parameters ) -> Return Type in
Statements
}
大括号（curly brace：卷曲的括号）里面是闭包内容， 小括号（）里面是参数argument ，->
后面写返回值的类型，在 in 后面开始写 闭包体语句。in 来提示 闭包中参数和返回值的定义都已完成。
