从地图的列表表示到Scala中的真实地图 [英] From a List representation of a Map, to a real Map in Scala

问题描述

我想将一个Seq的键/值转换为一个Map。序列的第一个元素是保留的，所以对的列表从1开始。

I want to transform a Seq of keys/values to a Map. The first element of the sequence is reserved, so the list of pairs starts in the position 1.

问题是：是否可以实现这个函数使用更多的函数方式吗？

The question is: Is possible to implement this function using a more functional way?

def list2Map(plainMap:Seq[String]) = {
  var map = Map[String, String]()
  var idx = 1;
  while(plainMap.size > idx) {
    val key = plainMap(idx)
    idx += 1
    val value = plainMap(idx)
    idx += 1

    map = map + (key -> value)
  }

  map
}

assert( list2Map( Seq("reserved slot","key0","value0","key1","value1","key2","value2") ) == Map( ("key0"->"value0"),("key1"->"value1"),("key2"->"value2") ) )

我是Scala中的新成员，我知道有很多不同的方法来迭代集合，但是我没有发现forEach方法从元素1开始每次迭代读取两个元素。

I am new in Scala, and I know that there are a lot of different ways to iterate over a collection, but I don't found a forEach way to read two elements per iteration, starting in the element 1.

PS：谢谢大家。我和大家一起学习了很多回应!!

PS: Thanks folks. I am learning a lot with everyone response!!

推荐答案

list.drop（1）.grouped（ 2）.map {x => x.head - > x.last} .toMap

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