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)")
//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)")