继承

特质：trait

这是用来表示多继承。多继承！

要注意with，关键字

trait Tall {
  var height:Int = 180
}
trait Eye {
  var beautifulEye:String = "大眼睛"
}
class Girl extends Tall with Eye {}

def main(args: Array[String]): Unit = {
  val girl1 = new Girl()

    println(girl1.beautifulEye)
    println(girl1.height)
    }                   结果：大眼睛
}                             180

trait

具体可以写什么 === abstract class

    1.抽象属性
    2.具体属性
    3.抽象方法
    4.具体方法

子类一定要实现所有的父类中的抽象成员（属性，方法）

trait Tall {
  var height:Int = 180
  var name:String
  def say():Unit = {println(s"${name}")}
  def cry():Unit
}
trait Eye {
  var beautifulEye:String = "大眼睛"

  var age:Int
}
class Girl extends Tall with Eye {
  var name: String = "女士"

  def cry(): Unit = {
    println("cry.....")
  }

  var age: Int = 18
}

def main(args: Array[String]): Unit = {
  val girl1 = new Girl()
  girl1.say()
  println(girl1.age)
  println(girl1.name)
  girl1.cry()
  println(girl1.beautifulEye)
  println(girl1.height)
}