Bizzare!
Bizarre, but documented:
       The auto-increment operator has a little extra builtin magic to it.  If
       you increment a variable that is numeric, or that has ever been used in
       a numeric context, you get a normal increment.  If, however, the
       variable has been used in only string contexts since it was set, and
       has a value that is not the empty string and matches the pattern
       "/^[a-zA-Z]*[0-9]*\z/", the increment is done as a string, preserving
       each character within its range, with carry:

           print ++($foo = '99');      # prints '100'
           print ++($foo = 'a0');      # prints 'a1'
           print ++($foo = 'Az');      # prints 'Ba'
           print ++($foo = 'zz');      # prints 'aaa'

In reply to Re: Amusement in Auto-Increments by JavaFan
in thread Amusement in Auto-Increments by kiz

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