Scala中的case class

别惊鹊2024-11-13 9:35

case class是Scala中一种特殊的类，它用于创建不可变的数据容器

Scala 复制代码

//Set特点：去重
//设置一个Book。三个属性：书名，作者，价格
class Book1(bookName:String,author:String,price:Double){
  //判断一个类的两个对象是否相等
//  override def equals(obj: Any): Boolean = {
//    //判断依据是书名相同
//    val o=obj.asInstanceOf[ttttt.Book]
//    o.bookName==bookName
//  }
//
//  override def toString: String = s"书名是：$bookName,作者是：$author,价格是：$price"
//
//  override def hashCode(): Int = bookName.hashCode
}

//casa class的特点
//1.数据是只读的
//2.可以省略new
//3.它内置实现了一些方法
//  equals hashCode toString
case class BookCase(bookName:String,author:String,price:Double)

object t4 {
  def main(args: Array[String]): Unit = {
    val book1=new Book1("西游记","吴承恩",100)
    val book11=new Book1("西游记","吴承恩",100)
    val set1=Set(book1,book11)
    println(set1)


    val book2=BookCase("西游记","吴承恩",100)
    val book3=BookCase("西游记","吴承恩",100)

    println(book1 == book11)
    println(book2 == book3)

    println(book1)//println会自动去调用对象的toString方法
    println(book2)


  }
}