From: Thomas Link <samul@...>
Date: 2003-12-11T00:22:02+09:00
Subject: Re: ruby 1.8.0: Error on "%02d" % "08" or "%02d" % "09"

>>`%': invalid value for Integer: "08" (ArgumentError)
> 
> 
> irb(main):003:0> "%02d" % 08
> SyntaxError: compile error
> (irb):3: Illegal octal digit
>         from (irb):3
> 
> Leading zeros have a special meaning with integer values.

Your example is different as the second argument is not a string -- 
although I understand what you're hinting at. Anyway, converting the 
string into an integer in advance (as proposed by the previous poster) 
actually solved the problem. I nevertheless think it's inconsistent that 
string#to_i didn't expect an octal number too when string#% does so.

Cheers,
Thomas.