数组--简单的排序

 //1.定义一个数组

    let item=["B","C","H","E","A","x","F"];

//2.定义一个新变量来接收

   let sortItem=itemString.sort{ $0 < $1 };    ==>从小到大排序（A-Z）

   print("排序后的值----(sortItem)")