From: Bulat Ziganshin <bulatz@...>
Date: 2002-10-23T18:28:29+09:00
Subject: Re: Things That Newcomers to Ruby Should Know (10/16/02)

Hello Ian,

Tuesday, October 22, 2002, 7:30:19 AM, you wrote:

IM> I understand that, but since 'a' already exists prior to assigning a + b
IM> to it, why does it need to be recreated? Where strings are concerned,
IM> I don't see why this would be any different to 'a << b'.

main problem is that object pointed by 'a' mauy be also pointed by
another variable an if you change this object directly your code wil
have SIDE EFFECT. are you really need this? :) so '<<' and other
methods changing object itself must be used very carefully, preferably
for local variables and other "own" objects

example of this side effect:

def a(s)
  s << '!'
  s += '?'
  return s
end

x='1'
y=a(x)
p x,y

-- 
Best regards,
 Bulat                            mailto:bulatz@integ.ru