scala进阶23-for与模式匹配

object For_Advanced {  def main(args: Array[String]): Unit = {    for (i <- List(1, 2, 3, 4, 5)) println(i)    //index绑定了一个别名,叫Flink,内部是模式匹配,匹配到Flink后设置别名给index    for(index@"Flink" <- List("Hadoop", "Spark", "Flink")) {      println(index)    }    //for与元祖模式匹配    for ((language, "Hadoop") <- Set("Scala" -> "Spark", "java" -> "Hadoop")) {      println(language)    }    //类型限定    for((k, v: Int) <- List(("spark" -> 5), ("Hadoop" -> "hdfs"))) {      println(k)    }  }}