List练习题

 

 
 
import scala.collection.mutable.ListBuffer
 
class Book(var name:String,var author:String,var price:Double){
 
}
 
object Test20_1 {
  def main(args: Array[String]): Unit = {
    var bookList = ListBuffer[Book]()
    // 创建六本图书对象并添加到列表尾部
    bookList += new Book("Book1", "Author1", 20.0)
    bookList += new Book("Book2", "Author2", 25.0)
    bookList += new Book("Book3", "Author3", 18.0)
    bookList += new Book("Book4", "Author4", 30.0)
    bookList += new Book("Book5", "Author5", 22.0)
    bookList += new Book("Book6", "Author6", 15.0)
 
    // 创建一本图书对象并添加到列表头部
    bookList.prepend(new Book("NewBook1", "NewAuthor1", 28.0))
 
    // 创建一本图书对象并添加到列表第三个位置
    bookList.insert(2, new Book("NewBook2", "NewAuthor2", 32.0))
 
    // 根据图书名称查询是否在列表中
    def isBookInList(name: String): Boolean = {
      for (book <- bookList) {
        if (book.name == name) return true
      }
      false
    }
 
    val bookNameToSearch = "Book3"
    println(s"Is $bookNameToSearch in the list? ${isBookInList(bookNameToSearch)}")
 
    // 从列表中删除第四本书
    bookList.remove(3)
 
    // 图书价格按从高到低排序
    val sortedList = bookList.sortBy(-_.price)
 
    // 遍历图书列表并打印每本书的详细信息
    println("Book List Details:")
    for (book <- sortedList) {
      println(s"Name: ${book.name}, Author: ${book.author}, Price: ${book.price}")
    }
 
    // 展示全部的总的金额
    val totalAmount = sortedList.map(_.price).sum
    println(s"Total amount: $totalAmount")
  }
}