set的特点

package test_27case class Book(var bookName:String, var author: String, var price: Double){}object caseclass{def main(args: Array[String]): Unit = {val set1 = scala.collection.mutable.Set[Book]()val book1 =new Book("西游记","吴承恩",100)val book2 =new Book("西游记","吴承恩",100)val book3 =new Book("西游记","吴承恩",100)println(book1 ==book2)set1 +=book1set1 +=book2set1 +=book3set1.foreach(s =>{println(s.author)})}}

结果是：true
              吴承恩