Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
693 views
in Technique[技术] by (71.8m points)

swift - Property initializers run before 'self' is available

Seems like I'm having a problem with something that shouldn't be the case... But I would like to ask for some help.

There are some explanations here on the Stack I don't get.

Having two simple classes where one refers to another, as per below;

class User {
  lazy var name: String = ""
  lazy var age: Int = 0

  init (name: String, age: Int) {
      self.name = name
      self.age = age
  }
}

class MyOwn {
  let myUser: User = User(name: "John", age: 100)
  var life = myUser.age 
  //Cannot use instance member 'myUser' within property initializer
  //property initializers run before 'self' is available
}

I get the commented compile error. May someone please tell me what should I do to solve the case?

Many thanks to any good man for help!

question from:https://stackoverflow.com/questions/43550813/property-initializers-run-before-self-is-available

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

As correctly pointed by vadian you should create an init in such scenarios:

class MyOwn {
    let myUser: User
    var life: Int

    init() {
        self.myUser = User(name: "John", age: 100)
        self.life = myUser.age 
    }
}

You can't provide a default value for a stored property that depend on another instance property.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...