$ pry
[1] pry(main)> a
NameError: undefined local variable or method `a' for main:Object
from (pry):1:in `__pry__'
[2] pry(main)> if 1 == 2
[2] pry(main)*   a = 'aaa'
[2] pry(main)* end  
=> nil
[3] pry(main)> a
=> nil

else
  a = nil

给省了