From: Timothy Hunter <cyclists@...>
Date: 2005-12-23T06:32:50+09:00
Subject: Re: String > Integer Conversion Problem

Matthew Feadler wrote:
> First, thanks all very much for the lively discussion thus far.  It's 
> proven very useful.
> 
> Timothy Hunter wrote:
> 
>>The Integer() method raises ArgumentError if given an empty,
>>non-numeric, or otherwise non-well-formed string.
> 
> 
> Hmm...apparently not--at least not w/ 1.8.2 on mswin32.
> 
> This:
> 
>   begin
>     one, two = ARGV.map{ |n| Integer(n) }
>   rescue ArgumentError
>     puts "Usage..."
>     exit
>   end
> 
>   puts one
>   puts two
> 
> Outputs:
> 
>   nil
>   nil
> 
> When fed no command-line arguments.  It does work as intended if any of 
> the args are non-empty strings, however.

That would be because Integer is never called. If there are no 
command-line arguments, ARGV is empty, there's nothing to map.