From: Timothy Hunter <cyclists@...>
Date: 2005-12-22T08:17:49+09:00
Subject: Re: String > Integer Conversion Problem

Matthew Feadler wrote:
> Retro thanks to all who helped me with my last post.  I'm certainly more 
> comfortable with Ruby now than then, but still a newbie as the following 
> will surely demonstrate.
> 
> Below, you can see that I'm checking command-line arguments to the 
> program for various conditions.  Unfortunately, because the args are 
> stored as strings, when I convert them via to_i, empty and non-numerical 
> strings become 0.  0 is an acceptable element in this program, therefore 
> I can't use it to test for invalid input.  I've worked around this (sort 
> of), by creating two sets of variables for the arguments (one set as 
> strings, one set as integers).  Unfortunately, this complicates the 
> code, and more importantly, leaves me stumped concerning how to test for 
> non-numeric values.

The Integer() method raises ArgumentError if given an empty, 
non-numeric, or otherwise non-well-formed string.