Question

我有一个元组

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我需要一个函数来转换上面映射的字符串的第三个字母

示例：

{("ABC", "123"),("DEF", "456"),("GHI", "789")}

我该怎么做？我是Scala编程的新手，希望在此提供任何帮助。

Answer 1

假设您有一个元组列表

val listOfTuples = List(
  ("ABC", 123),
  ("DEF", 456),
  ("GHI", 789),
)

现在要将其转换为地图，您可以编写以下函数

val endOfMap = "ADF_MESSAGE" + (listOfTuples.size + 1)

listOfTuples.zipWithIndex.map {
  case ((str, int), index) =>
    (str.take(3) + "_MESSAGE" + (index + 1)) -> (int + "_MESSAGE" + (index + 1))
}.toMap + (endOfMap -> endOfMap)

这将为您获取输出

res0: scala.collection.immutable.Map[String,String] = Map(ABC_MESSAGE1 -> 123_MESSAGE1, DEF_MESSAGE2 -> 456_MESSAGE2, GHI_MESSAGE3 -> 789_MESSAGE3, ADF_MESSAGE4 -> ADF_MESSAGE4)

Answer 2

将元组变成Map以便于查找。

val lookup = Seq(("ABC","123"), ("DEF","456"), ("GHI","789")).toMap

Seq("ABC_MESSAGE1", "DEF_MESSAGE2", "GHI_MESSAGE3", "ADF_MESSAGE4")
  .map(msg =>lookup.get(msg.take(3)).fold(msg)(_ + msg.drop(3)))
//res0: Seq[String] = List(123_MESSAGE1, 456_MESSAGE2, 789_MESSAGE3, ADF_MESSAGE4)

替换字符串的第三个字母的功能

2 个答案: