scala基础41-Set/Map/TreeSet/TreeMap

import scala.collection.mutableimport scala.collection.mutable.TreeSetimport scala.collection.immutable.TreeMapobject Test extends App{  //可变Set和List互操作  val data = mutable.Set.empty[Int]  data ++= List(1, 2, 3)  data += 4;  data --= List(2, 3)  println(data)  //Set是不可重复的,因此下面的操作不起作用  data += 1  println(data)  //清空Set  data.clear()  println(data)  //map操作  val map = mutable.Map.empty[String, String]  map("java") = "hadoop"  map("scala") = "spark"  println(map)  println(map("scala"))  //treeSet操作，要求内容可排序  val treeSet = TreeSet(9, 3, 6, 1)  println(treeSet) //打印时自动排序  val treeSetForChar = TreeSet("spark", "scala", "hadoop")  println(treeSetForChar)  //treeMap操作，要求内容可排序  var treeMap = TreeMap("scala" -> "spark", "java" -> "hadoop")  println(treeMap) //打印时自动排序}