zoukankan      html  css  js  c++  java
  • Scala 学习笔记之集合(4)

    集合的模式匹配操作:

    object CollectionDemo5 {
      def main(args: Array[String]): Unit = {
        //集合模式匹配1
        val ls = List(1, 2, 3, 4, 5)
        println(
          ls match {
            case List(1, 2, 3) => "List(1,2,3)"
            case List(1, 2, 3, 4) => "List(1,2,3,4)"
            case List(1, 2, 3, 4, 5) => "List(1,2,3,4,5)"
            case other => "No match"
          })
        //集合模式匹配2
        val ls2 = List(9, 2, 3, 4, 5, 6)
        println(
          ls2 match {
            case List(1, 2, 3) => "List(1,2,3)"
            case List(1, 2, 3, 4) => "List(1,2,3,4)"
            case List(_, _, 3, 4, x) => "List(1,2,3,4,5)" + x
            case _ => "No match"
          })
        //集合模式匹配3
        val ls3 = List(9, 2, 3, 4, 5, 6)
        println(
          ls3 match {
            case x :: y :: z => z
            case Nil => "No match"
          })
        //集合模式匹配4  
        val ls4 = (1, 2, 3, 4, 5, 6)
        println(
          ls4 match {
            case (_,_,x,_,_,_) => x
            case _ => "No match"
          })
    
      }
    }
    

    运行结果:

    List(1,2,3,4,5)
    No match
    List(3, 4, 5, 6)
    3

  • 相关阅读:
    第二章初识MySQL
    第一章 数据库
    Java&SQL7
    Java&SQL
    Java&SQL6
    Java&SQL5
    Java&SQL4
    Java&SQL3
    Java&SQL2
    博客地址已搬迁
  • 原文地址:https://www.cnblogs.com/AK47Sonic/p/7078378.html
Copyright © 2011-2022 走看看