# irb irb(main):001:0> puts x NameError: undefined local variable or method 'x' for main:Object from (irb):1 from /usr/bin/irb:11:in '<main>'
Okay. I expected that.
irb(main):002:0> x = x + 1 NoMethodError: undefined method '+' for nil:NilClass from (irb):2 from /usr/bin/irb:11:in '<main>'
Whoa. Did NOT expect that! Wait, so does that mean…?
irb(main):003:0> z = z => nil
Hmm. Okay. Well, time to call it a day.