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arraysscalatype-parameter

Scala - creating a type parametrized array of specified length

If in Scala IDE try the following:

val chars = Array[Char](256)

it is all fine. But if I do this:

val len = 256
val chars = Array[Char](len)

it says that it expects a Char instead of len? Why? I expect the behavior to be the same! Why does it think that I want to put that thing in the array instead of specifying it's size? As far as I know, there is no constructor for arrays that takes a single argument to place it inside the array.

Solution 
  • val chars = Array[Char](256)

    This works because 256 treated as a Char and it creates one-element array (with code 256)

    val len = 256
val chars = Array[Char](len)

    Here len is Int, so it fails

    To create array of specified size you need something like this

    val chars = Array.fill(256){0}

    where {0} is a function to produce elements

    If the contents of the Array don't matter you can also use new instead of fill: 

    val chars = new Array[Char](256)