Kotlin 基础教程之类、对象、接口

interface A {
  fun bar()
  fun foo() {
  // 可选方法体
  }
}

class Child: A {
  override fun bar() {
    // todo
  }
  override fun foo() {
    super.foo()
  }
}

class Person constructor(name: String) {...}

class Person(name: String) {...}

class Persion(name: String) {
  private val firstName: String = name
  private var age: Int
  init {
    age = 10
  }
}

class Persion(val name: String, var age: Int) {...}

class Persion public @Inject constructor(val name: String) {...}

class Persion(val name: String) {
  constructor(name: String, age: Int): this(name) {
    // todo
  }
}

val persion = Persion("jason")

open class Base {
  open fun v() {...}
  fun nv() {...} // can't be override
}

class Other: Base() {
  override fun v() {...}
}

open class Foo {
  open val x: Int = 0
}

class Bar(override val x: Int): Foo {...}

class Bar1: Foo() {
  override var x: Int = 0 // override to var
}

abstract class Base {
  abstract fun v()
}

class Foo {

companion object {
  fun v() {}
}
}

interface A {
  val x: Int
}

class B: A {
  override val x: Int = 10
}

object B {
  fun foo() {
    // do something
  }
}

class A {
  fun bar() {
   B.foo()
  }
}