1.在工具栏选择 "association" (关联).2.编辑role B 属性 open specital , role B detail ,multiplic(重数) 为1,勾选 "Aggregate",不勾选"navigable".containment of Data (传递方式)为by value. 3.编辑role A 属性 role A detail ,勾选"navigable" ,不勾选 "Aggr
//: Playground - noun: a place where people can play import UIKit var str = "Hello, playground" //-------------------- 类和属性 -------------------- class Role{ //成员属性 var id = "" var money = //静态属性 static var method = "RNA" //子类