Kotlin의 구성 방법 또는 속성의 클래스

주 구조 방법과 문장 블록 초기화

class User constructor(_nickname: String){
    val nickname: String
    init { 
        nickname = _nickname
    }
}

class User2 constructor(_nickname: String){
    val nickname = _nickname
}

class User(val nickname:String)

class User(val nickname: String,val isSubscribed: Boolean = true)

open class User(val nickname: String){...}

class TwitterUser(name:String) : User(name){...}

open class Button
class RadioButton : Button()

class Secretive private constructor(){...}

다른 방식으로 부류를 초기화하다

class MyButton : View{

    constructor(ctx:Context):this(ctx, null)
    constructor(ctx: Context,attr: AttributeSet?):super(ctx,attr) 
}    

인터페이스에서 설명하는 속성을 실현하다

interface User {
    val nickname: String
}

  class PrivateUser(override val nickname: String) : User 

  class SubscribingUser(val email: String) : User {
      override val nickname: String
          get() = email.substringBefore("@")
  }

class FaceBookUser(val accountId：Int) : User {
    override val nickname = getFacebookName(accountId)
}

interface User {
    val email: String
    val nickname: String
        get() = email.substringBefore("@")
}

Getter 또는 setter를 통한 지원 필드 액세스

class User(val name: String){
    var address: String = "unspecified"
        set(value) {
            println("Address was changed for $name: $address -> $value") 
            field = value 
        }
}

val user = User("kangdongpu");
user.address = "HeBei,SJZ"

Address was changed for kangdongpu: unspecified -> HeBei,SJZ

액세스 가시성 수정

class LengthCounter {
    var counter:Int = 0
    private set 

    fun addWord(word:String){
        counter+=word.length
    }
}