CODEWITHSUNDEEP
scalarandom
david hol
david hol

Reputation: 1280

Scala: how to get random element form given list

I want to pick random element from given list:

  def randomAlphaNumericChar(): Char = {
    val ALPHA_NUMERIC_STRING = "aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ0123456789".toCharArray
    Gen.oneOf(ALPHA_NUMERIC_STRING)
  }

So currently this now compile:

type mismatch; found : org.scalacheck.Gen[Char] required: Char Gen.oneOf(ALPHA_NUMERIC_STRING)

Upvotes: 0

Views: 334

Answers (3)

elm
elm

Reputation: 20435

For 

val xs = ('a' to 'z') ++ ('A' to 'Z') ++ (1 to 9)

try

xs.maxBy(_ => scala.util.Random.nextInt)

Here maxBy applies a function to each element of the collection and then selects the maximum value returned by the function applied to each element. In this case the function is a random value returned from Random.nextInt.

Upvotes: 1

haluk
haluk

Reputation: 1178

  def randomAlphaNumericChar(): Char = {
  /*
     ASCII Codes
     [0-9]: (48 to 57)
     [A-Z]: (65 to 90)
     [a-z]: (97 to 122)
  */
    val alphabet = (48 to 57) union (65 to 90) union (97 to 122)
    val i = scala.util.Random.nextInt(alphabet.size)
    alphabet(i).toChar
  }

Upvotes: 1

hipjim
hipjim

Reputation: 128

Something like this will work

def randomAlphaNumericChar(): Char = {
    val ALPHA_NUMERIC_STRING = "aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ0123456789".toList
    scala.util.Random.shuffle(ALPHA_NUMERIC_STRING).head
}

Upvotes: 0

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