Ruby challenge - diamond method

diamond.rb

## Method 1 (used 2 methods)

def diamond(max_width)
  string = ""

  if max_width < 3
    puts "*"  if max_width == 1
    puts "**" if max_width == 2
    return nil
  end

  if max_width.even?
    width = 2
  else
    width = 1
  end

  string << create_row(width, max_width)

  while width < max_width
    width += 2
    string << "\n"

    string << create_row(width, max_width)
  end

  while width > 2
    width -= 2
    string << "\n"

    string << create_row(width, max_width)
  end

  puts string
end

def create_row(width, max_width)
  spaces = (max_width - width) / 2
  (" " * spaces) + ("*" * width)
end

#######################################################################

## Method 2

def diamond(max_width)

  if max_width.even?
    array = (2..max_width).to_a.select{|n| n.even?}
  else
    array = (1..max_width).to_a.select{|n| n.odd?}
  end
  array = array + array.reverse[1..-1]

  string = ""
  array.each_with_index do |width, index|
    spaces = (max_width - width) / 2
    string << (" " * spaces) + ("*" * width)
    string << "\n" unless index == array.length - 1
  end

  puts string
end