scala中获取Map中key和value的方法

val  scores=Map("Alice"->10,"Bob"->3,"Cindy"->8)
//     获取所有的key
val nameList=scores.map(_._1)
//     map 函数返回List
println(nameList.getClass)
遍历list中的元素
nameList.foreach((x:String)=>print(x+" "))
输出 ：Alice Bob Cindy

//     或取所有的value

val   resultList=scores.map(_._2)
resultList.foreach {(x:Int)=>print(x+" ") }
输出：10 3 8

val  scores=List((1,"Alice",10),(2,"Bob",30),(3,"Cindy",50))
//   获取所有Tuples中的第三个元素
val  scoreList=scores.map(_._3)
for (scores<-scoreList){
print(scores +" ")
}

val  keyList=List("Alice","Bob","Cindy")
val valueList=List(10,3,8)
val scores=keyList.zip(valueList).toMap
println(scores)
//    Map(Alice -> 10, Bob -> 3, Cindy -> 8)