gistfile1.rb

irb(main):001:0> def doubler(start)
irb(main):002:1>   puts start
irb(main):003:1> end
=> nil
irb(main):004:0>
irb(main):005:0* doubler(2)
2
=> nil
irb(main):006:0> doubler(4)
4
=> nil
irb(main):007:0> doubler(8)
8
=> nil


--------------------------


irb(main):001:0> def doubler(start)
irb(main):002:1>   puts start
irb(main):003:1>
irb(main):004:1*   if start < 10
irb(main):005:2>     doubler(start * 2)
irb(main):006:2>   end
irb(main):007:1> end
=> nil
irb(main):008:0> doubler(2)
2
4
8
16
=> nil