From: Rob Biedenharn <rob@...>
Date: 2013-04-18T05:33:09+09:00
Subject: Re: String index produces unanticipated result

On 2013-Apr-17, at 16:24 , Thomas Luedeke wrote:

> I have the following string I am pulling from a file (asterisks used to
> show boundaries of line, and are not actually there:
> 
> *    9    3    3    0    0*
> 
> I want to test to see if a "9" is in the first five columns of the line.
> Typically it is in column five, but not necessarily.
> 
> I tried the "puts line.strip[0]" command, which returns "57".  Huh?
> Where did "57" come from??  Same thing happens with strip!.
> 
> Why isn't this simply removing the leading white space and returning
> "9"??  I don't understand how to accomplish my task now.
> 
> I tried the online irb, and it gave me "9", like I'd have expected.

Your local ruby is probably <1.9 and String#[] returns the integer value of the referenced character.

irb1.8.7> 57.chr
#1.8.7 => "9"

The online version is probably >=1.9 and String#[] returns a one-character string.

irb2.0.0> "    9    3    3    0    0".strip[0]
#2.0.0 => "9"

-Rob