Scala深入浅出实战经典：40,Set、Map、TreeSet、TreeMap操作代码实战

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package com.dt.scalaInAction.demo_040import scala.collection.immutable.TreeSetimport scala.collection.immutable.TreeMap/** * Set、Map、TreeSet、TreeMap操作代码实战 */object Set_Map {    def main(args: Array[String]): Unit = {        //mutable.Set        val data = scala.collection.mutable.Set.empty[Int]        //加入集合        data ++= List(1, 2, 3)        println(data)   //Set(1, 2, 3)        data += 4        println(data)   //Set(1, 2, 3, 4)        //移除集合        data --= List(2, 3)        println(data)   //Set(1, 4)                data += 1        println(data)   //Set(1, 4)                data.clear        println(data)   //Set()                        //mutable.Map          val map = scala.collection.mutable.Map.empty[String, String]        //添加键值        map("Java") = "Hadoop"        map("Scala") = "Spark"        //覆盖修改        map("Java") = "xxx"  // 等价于 map.put("Java", "xxx")        println(map)  //Map(Scala -> Spark, Java -> Hadoop)        println(map("Scala"))  //Spark                //immutable.TreeSet 有序的Set        val treeSet = TreeSet(9, 3, 1, 8, 0, 2, 7, 4, 6, 5)        println(treeSet)  //TreeSet(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)        val treeSetForChar = TreeSet("Spark", "Hadoop", "Scala")        println(treeSetForChar)  //TreeSet(Hadoop, Scala, Spark)                 //immutable.TreeMap          val treeMap = TreeMap("Scala" -> "Spark", "Java" -> "xxx", "j" -> "k")        println(treeMap)   //Map(Java -> xxx, Scala -> Spark, j -> k)                    }}

以上内容是从王家林老师DT大数据课程第40讲的学习笔记和个人整理。

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第40讲视频网站地址: http://pan.baidu.com/s/1ntDZ501

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