From: dblack@...
Date: 2005-12-22T09:21:39+09:00
Subject: Re: String > Integer Conversion Problem

Hi --

On Thu, 22 Dec 2005, 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.
>
> So, the program does what I want, except when the args are non-numeric
> strings, and the code seems uglier than it ought to be.

In addition to the other suggestions, you might find scanf useful:

   require 'scanf'
   arg0, arg1 = ARGV.join.scanf("%d%d")

or something like that.


David

-- 
David A. Black
dblack@wobblini.net

"Ruby for Rails", from Manning Publications, coming April 2006!
http://www.manning.com/books/black