Kotlin笔记4-面向对象编程2-接口,数据类与单例类

3.2 面向对象编程2

• 接口

interface

​​Example:​​

interface Study {
    fun readBooks()
    fun doHomework(){
        println("do homework default implementation.")
    }
}

​​继承父类与实现接口​​

class Student5(name: String, age: Int) : Person2(name, age), Study {
    override fun readBooks() {
        println("$name is reading.")
    }

    override fun doHomework() {
        println("$name is doing homework.")
    }
}

​​面向接口编程: 多态​​

fun main() {
    val student = Student5("Jack", 19)
    doStudy(student)
}

fun doStudy(study: Study) {
    study.readBooks()
    study.doHomework()
}

​​接口默认实现​​

interface Study {
  fun readBooks()
  fun doHomework() {
    println("do homework default implementation."
  }
}

• 函数的可见性修饰符

Kotlin,Java修饰符对照