Scala的set

//Set的特点：唯一（元素不相同）；无序
case class Book(var bookName:String,var author:String,var price:Double){

}
object test27 {
  def main(args: Array[String]): Unit = {
    //定义一个可变set
    val set1 = scala.collection.mutable.Set[Book]()

    //向Set中添加两条一样的数据
    val book1 = new Book("西游记","吴承恩",99)
    val book2 = new Book("西游记","吴承恩",99)
    val book3 = new Book("西游记","吴承恩",99)

    //book1 == book2？
    println(book1 == book2) // false 因为 book1和book2 地址不同

    set1 += book1
    set1 += book2
    set1 += book3

    set1.foreach(s=>{
      println(s.author)
    })
  }
}