【scala】 scala 映射和元组操作(四)

 

1、映射  Map

   定义 ,取值，遍历,排序

2. 元组

定义，取值，拉链操作

import scala.collection.mutable

/**
  *  映射和元组
  *
  * @author xwolf
  * @date 2017-04-12 11:23
  * @since 1.8
  */
object MapTest {

  def main(args: Array[String]): Unit = {
    tuple()
  }

  private def map(): Unit ={
    //定义映射 ->对偶操作
    var map =Map("id"->1,"name"->"王思琪",("age",10))

    var twoMap = Map("detail"->"优秀屌丝","state"->0)
    // += 添加K-V
    map += ("birth"->"20160101")
    //移除 key value
    map -= "id"
    //两个映射合并
    val newMap = map ++ twoMap
    println(newMap)
    println(map("name"))//map取值
    val name = if (map.contains("name1")) map("name") else None
    println(name)
    //映射遍历
    for (elem <- map) {
      println(elem)
    }

    for((k,v)<-map){
       println(k+","+v)
     }

    val keys = map.keySet
    for(k<-keys){
      println("k="+k+",value="+map(k))
    }

    // k v 互换 生成新的map
    val kMap = for((k,v)<-map) yield (v,k)
    println(kMap)

    //有序map 底层是java 的TreeMap
    val sortMap= mutable.SortedMap("a"->1,"age"->122,"state"->0,"name"->"老王")
    println(sortMap)

  }

  /**
    * 元组操作
    */
  def tuple(): Unit ={
    //元组定义
    val tuple =(1,2,12,4,15)
    println(tuple)
    println(tuple._3)//获取第三个元素,非下标
    println(tuple _3)//获取第三个元素,非下标

    val one = Array("Hello","Scala","Java")
    val two =Array(1,2,3)
    //拉链操作 将两个数组合并为Map
    val ou =one.zip(two)
    println(ou.toBuffer)

  }

}