From: Walton Hoops <walton@...>
Date: 2009-12-22T10:57:40+09:00
Subject: Re: Symbols vs. constants?

> -----Original Message-----
> From: Young H. [mailto:armywide@gmail.com]
> Hi,
> 
> It seems to me a constant can be changed during the runtime.
> 
> > Z="hello"
> => "hello"
> > Z=1234
> (irb):11: warning: already initialized constant Z
> => 1234
> > Z
> => 1234
> 
> So does it mean, it can be changed, but not encouraged?

In fact it is greatly discouraged.  There is never, ever
a reason to change a constant once it is set.  If you need
something that acts like a constant, yet can be reassigned
there is a construct for that: it's called a variable.

Reassigning constants implicitly gives the next person to 
work on the code permission to beat you about the head with
a large trout.