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scala

Convert Iterable[Any] to string in scala

I was trying to convert Iterable[Any] to String in scala

val enrichmentExpr: Iterable[Any]
// enrichmentExpr:List(List(test string1, test string2))

not able to convert using mkString:

val newenrichmentExpr = enrichmentExpr.mkString
println(s"newenrichmentExpr:$newenrichmentExpr")     
// newenrichmentExpr:List(test string1, test string2)

below is the expected output

newenrichmentExpr:test string1, test string2

Solution

  • Try the following

    val result = enrichmentExpr
  .flatMap(_.asInstanceOf[List[List[String]]])
  .mkString(", ")

    The problem is that the Iterable you have is of type Any. You can't flatten directly. First you need to cast to the type List[List[String]] and then you would be able to flatten the collection. Once you did that, you can do the mkString with the expected result

    The code above will solve the problem you are having, but it will bring some other risks. Since your Iterable is of type Any, you could have any possible type of value different than a List or some other value that can't be flattened. If that happens, you will have an error at runtime.

    The compiler doesn't know how to flatten type Any inside the Iterable. Maybe you should consider to define the variable enrichmentExpr with another type of value.

    The following text with good practices should help you

    Avoid using Any or AnyRef or explicit casting, unless you've got a really good reason for it. Scala is a language that derives value from its expressive type system, usage of Any or of typecasting represents a hole in this expressive type system and the compiler doesn't know how to help you there.