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import scala.collection.mutable.ListBuffer
case class Book(id:String,bookName:String,author:String,price:Double,var amount:Int)object p4 {def main(args: Array[String]): Unit = {//2val BookList = ListBuffer[Book]()//3BookList += Book("001", "b1", "a1", 23, 42)BookList += Book("002", "b2", "a2", 55, 77)BookList += Book("003", "b3", "a3", 82, 11)println(BookList)//4val book1 =Book("004", "b4", "a4", 30, 24)
//如果已经包含这本书，直接去修改数量val rs=BookList.find(_.id==book1.id)if(rs.isEmpty){println("没有")BookList+=book1}else{println("有")val s=rs.get//拿出具体的数据s.amount+=book1.amount//数量增加}//5var bookName="b4"val rs1=BookList.find(_.bookName==bookName)if(rs1.isEmpty)println(s"《$bookName》不存在")elseprintln(s"《$bookName》存在")//6bookName = "b1"val rs2 = BookList.find(_.bookName == bookName)if (rs2.isEmpty)println(s"《$bookName》不存在,删除失败")else {println(s"《$bookName》存在,删除成功")BookList-=rs2.get}//7val id = "002"val rs3=BookList.find(_.id==id)if(rs3.isEmpty)println(s"$id 不存在,删除失败")else {println(s"$id 存在,删除成功")BookList-=rs3.get}//8val orderList=BookList.sortWith((a,b)=>a.price>b.price)//9orderList.foreach(el=>{println(s"书名${el.bookName}，作者${el.author}，价格${el.price}，数量${el.amount}")})//10var sum:Double=0BookList.foreach((el=>{sum+=(el.amount*el.price)}))println(s"总的金额是：${sum}")}
}