Swift教程之结构体

import Foundation//结构体struct Student{    var name = ""    var age = 0        func test()    {        print("test")    }}//所有结构体都有一个自动生成的成员逐一构造器，用于初始化新结构体实例中成员的属性let vga = Student(name: "小明", age: 2)let someStudent = Student()print(vga.name)print("\(someStudent.age)")someStudent.test()class Classes{    var student = Student()    var isOK = false    var address: String?}let someClasses = Classes()//Swift 允许直接设置结构体属性的子属性someClasses.student.age = 20print(someClasses.student.age)//类是引用类型，引用的是已存在的实例本身而不是其拷贝。let stu = Student(name:"阿杰", age: 1080)let cla = Classes()cla.student = stucla.isOK = truecla.address = "北京西城区"let alsocla = claalsocla.address = "上海浦东"/*等价于 ( === )恒等于不等价于 ( !== )*/if cla === alsocla{    print("cla 与 alsocla 是等价的")}/*“等价于 ===”表示两个类类型(class type)的常量或者变量引用同一个类实例。“等于 ==”表示两个实例的值“相等”或“相同”*/