I was reminiscing recently about what my programming exercises were at high school. I started on Turbo Pascal.

This is was one of the first, simply to draw a diamond shape, that looked like this:

          *
         ***
        *****
       *******
      *********
     ***********
    *************
   ***************
  *****************
 *******************
*********************
 *******************
  *****************
   ***************
    *************
     ***********
      *********
       *******
        *****
         ***
          *

I remember it taking forever, but loving it. So decided to write it out in ruby.

s = 10
(-s..s+1).each do |y|
  (-s..s+1).each do |x|
   print x.abs + y.abs > s ? ' ' : '*'
  end
  puts
end

Alternative solution:

s = 10
s.times {|u| puts ' ' * (s - u.to_i) + '*' * (u + u.to_i) }
s.downto(0).each {|u| puts ' ' * (s - u.to_i) + '*' * (u + u.to_i) };