11.6.3 遍历 Map

package com.atguigu.day11.map

import scala.collection.mutable

object MapDemo5 {
  def main(args: Array[String]): Unit = {

    val map1 =
      mutable.Map("a" -> 1, "c" -> 2, "b" -> 3)
    //方法1: k v 一起遍历
    for ((k, v) <- map1) {
      println(k + " = " + v)
    }
    println("-----------")
    // 方法2: 只遍历key
    for (k <- map1.keys) {
      println("k = " + k)
    }
    println("-----------")
    // 方法3: 只遍历value
    for (v <- map1.values) {
      println("v = " + v)
    }
    println("-----------")
    // 方法4: 遍历出来tuple2, 然后 _1 _2 来获取k 和v
    for (kv <- map1) {
      println(kv._1 +" = " + kv._2)
    }
  }
}