面向对象同步练习.docx

面向对象同步练习1. 在Swift中具有面向对象特征的数据类型有（ACD）。A. 枚举B. 元组C. 结构体D. 类2. 判断正误：在Swift中，类具有面向对象的基本特征，即封装性、继承性和多态性。T3. 判断正误：Swift中的枚举、类和结构体都具有继承性。F4. 有下列枚举类型代码：enumProductCategory caseWashers , Dryers, Toastersvar product = ProductCategory.Toasters枚举类型能够与switch语句结合使用，下列使用switch语句不正确的是（C）。A.switch product case .Washers: println(洗衣机)case .Dryers : println(烘干机)default: println(烤箱) B.switch product case .Washers: println(洗衣机)case .Dryers : println(烘干机)case .Toasters : println(烤箱) C.switch product case .Washers: println(洗衣机)case .Dryers : println(烘干机) D.switch product case .Washers: println(洗衣机)default: println(烤箱) 5. 有下列枚举类型代码：enumProductCategory : String caseWashers = washers, Dryers = dryers, Toasters = toasters 下列代码中能够成功输出烤箱的是（AC）。A.if (product.toRaw() = toasters) println(烤箱) B.if (product.toRaw() = .Toasters) println(烤箱) C.if (product = .Toasters) println(烤箱) D.if (product = toasters) println(烤箱) 6. 下列代码是在C语言中定义了联合类型的示例。typedefunion char c; int a; double b; Number; 请把它改造成为Swift代码。7. 判断正误：Swift中枚举是值类型，而类和结构体是引用类型。8. 判断正误：Swift中结构体有属性、方法、下标、构造器和析构器。9. 判断正误：由于具有面对对象的特征，所以枚举、类和结构体都可以使用恒等号=进行比较。10. 下列有关类型嵌套正确的是（）。A.class a class b enum c case c(Character)struct d B.enumNumber case c(Character)case a(Int) case b(Double) class d struct e C.struct c class b D.struct c1 class b class a 11. 运行下列代码的输出结果是（）。var cod : String? = a fishvar dab : String? = cod println(cod = (cod) cod = nilprintln(cod = (cod) println(dab = (dab) A.cod = a fish cod = nildab = nilB.cod = nilcod = nildab = a fish C.cod = a fish cod = nildab = a fish D.cod = nilcod = nildab = nil12. 下列语句能够正确执行的是（）。A.var optionalCod: Stringif optionalCod println(uppercase optionalCod = (optionalCod.uppercaseString) else println(optionalCod is nil) B.var optionalCod: String? if optionalCod println(uppercase optionalCod = (optionalCod.uppercaseString) else println(optionalCod is nil) C.var optionalCod: String? if optionalCod println(uppercase optionalCod = (optionalCod!.uppercaseString) else println(optionalCod is nil) D.var optionalCod: String! if optionalCod println(uppercase optionalCod = (optionalCod.uppercaseString) else println(optionalCod is nil) 13. 若有以下多个有关联关系类的定义：classPerson var residence: Residence? classResidence var rooms = Room() var numberOfRooms: Int return rooms.count subscript(i: Int) -Room return roomsi func printNumberOfRooms() println(The number of rooms is (numberOfRooms) var address: Address? classRoom let name: Stringinit(name: String) = name classAddress var buildingName: String? var buildingNumber: String? var street: String? func buildingIdentifier() -String? if buildingName return buildingName elseif buildingNumber return buildingNumber else returnnil 以下是类的访问代码，执行如下代码，说法正确的是（）。let john = Person() let joh