From: Adam Prescott <adam@...>
Date: 2011-11-10T05:27:10+09:00
Subject: Re: Strings are not equal

--14dae93b6356a9278d04b1531c89
Content-Type: text/plain; charset=UTF-8

On Wed, Nov 9, 2011 at 20:16, Mike S. <antsinyourpants128@gmail.com> wrote:

> I am testing two strings to see if they are equal.
> One string is just a simple string: "\17"
> The other is parsed to: "\17"
>

You might think so, but nope:

>> "\17"
=> "\u000F"
>> "\1#{7}"
=> "\u00017"
>> "\001"
=> "\u0001"
>> "\01"
=> "\u0001"
>> "\1"
=> "\u0001"
=> "\0017"
>> "\u00017"

The \ causes things to be escaped, with the subsequent 3 digits being an
octal number. "\001" == "\01" == "\1", and "\1#{7}" == "\1" + "#{7}" ==
"\001" + "#{7}"

To see the octal base:

>> "\001\005\1\01\010\060".bytes.to_a
=> [1, 5, 1, 1, 8, 48]

since, for example, 6*8^1 = 48. And since it expects numbers 0-7, 8 breaks
you out of it:

>> "\08"
=> "\u00008"

In other words, "\08" == "\008" == "\0008" == "\000" + "8". Finally, "\8"
== "8".

You can extend this to, e.g., "\xFA" for hexadecimal.

Beware the escaping character. :)

--14dae93b6356a9278d04b1531c89--