（Windows）Scala学习4--集、映射、迭代器

import scala.collection.mutable.Set
import scala.collection.mutable.Map
object Tuple {
  def main(args: Array[String]): Unit = {
    val tuple = ("wang",2019,3.3)
    println(tuple._1)
    println(tuple._2)
    println(tuple._3)
    println("-----------------------")
    //集
    var mySet = Set("hadoop","spark")
    println(mySet)
    //添加一个
    mySet += "scala"
    println(mySet)
    println("-----------------------")
    //映射
    val people = Map("xs" -> "student","ls" ->"teacher","jc" -> "police")
    println(people)
    //更新
    people("xs") = "xuesheng"
    //添加
    people += ("ys" -> "doctor","gr" -> "worker")
    println(people)
    println("-----------------------")
    //循环遍历映射
    for ((k,v)<- people)
      printf("Code is : %s and name is %s 
",k,v )   //k 为键  v为值
    println("-----------------------")
    for(k<- people.keys)
      println(k)
    println("-----------------------")
    for(v<- people.values)
      println(v)
    println("-----------------------")
    //迭代器
    val iter = Iterator("as","sd","df")
    //  while (iter.hasNext){
    //    println(iter.next)
    //  }
    for (elem <- iter)
      println(elem)
  }
}

结果：

wang
2019
3.3
-----------------------
Set(spark, hadoop)
Set(spark, scala, hadoop)
-----------------------
Map(jc -> police, xs -> student, ls -> teacher)
Map(jc -> police, gr -> worker, ys -> doctor, xs -> xuesheng, ls -> teacher)
-----------------------
Code is : jc and name is police 
Code is : gr and name is worker 
Code is : ys and name is doctor 
Code is : xs and name is xuesheng 
Code is : ls and name is teacher 
-----------------------
jc
gr
ys
xs
ls
-----------------------
police
worker
doctor
xuesheng
teacher
-----------------------
as
sd
df

 这一部分较容易理解，所以没有做过多解释。