Bit Counting

My:
object Kata {

def countBits(n: Int): Int = {
  def counting(n: Int, bits: Int=0):Int =
  {
    if(n/2!=0)
      if(n%2==1) counting(n/2, bits+1)
      else counting(n/2, bits)
    else bits+1
  }
  if(n==0) 0
  else
    counting(n)
}
}

Other:
object Kata {
  def countBits(n: Int): Int = Integer.bitCount(n)
}

object Kata {
  def countBits(n: Int): Int = n.toBinaryString.count(_ == '1')
}