阅读背景:

为什么在这个例子中使用force unwrapping?

来源:互联网 
let john = Person()
john.residence = Residence()

let johnsAddress = Address()
johnsAddress.buildingName = "The Larches"
johnsAddress.street = "Laurel Street"

john.residence!.address = johnsAddress
let john = Person()
john.residence = Residence(



你的当前访问异常,请进行认证后继续阅读剩余内容。

分享到: