继承

object class01 {
  
  class Animal() {
    def eat(): Unit = {
      println("animal eat......")
    }
  }

  class Dog extends Animal {

  }

  def main(args: Array[String]): Unit = {
    val d1 = new Dog()
    d1.eat()
  }
}

好处：不劳而获

object class01 {
  // 动物
  class Animal(var name: String = "动物") {
    val age: Int = 10

    def eat(): Unit = {
      println("animal eat......")
    }

    def run(): Unit = {
      println("animal run .....")
    }
  }

  // 狗
  class Dog() extends Animal {

  }

  def main(args: Array[String]): Unit = {
    val d1 = new Dog()
    d1.run()
    d1.eat()
  }
}