scala基础41-Set/Map/TreeSet/TreeMap

import scala.collection.mutable
import scala.collection.mutable.TreeSet
import scala.collection.immutable.TreeMap

object 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
}