zenwalker[~]$ irb -v
irb 0.9.5(05/04/13)
zenwalker[~]$ irb
irb(main):001:0> variable=2
=> 2
irb(main):002:0> variable+
irb(main):003:0* variable
=> 4
irb(main):004:0> variable
=> 2
irb(main):005:0> variable++
irb(main):006:0* variable
=> 4
irb(main):007:0> variable
=> 2
irb(main):008:0>