NewArrayFunctions

class Array

  def count
    c = 0
    each { |e| c += 1 if yield e }
    return c
  end unless method_defined?(:count)

  def get_nth( n )
    c = 0
    each { |e| c += 1 if yield e ; return e if c == n }
    return nil
  end unless method_defined?(:get_nth)

  def get_nth_index( n )
    c = 0
    for i in 0...size
      e = self[i]
      c += 1 if yield e ; return i if c == n
    end
  end

end