From: "David A. Black" <dblack@...>
Date: 2007-08-24T20:38:21+09:00
Subject: Re: something I just found out, am sharing (:newbish)

Hi --

On Fri, 24 Aug 2007, Robert Dober wrote:

> On 8/24/07, David A. Black <dblack@rubypal.com> wrote:
>> Hi --
>
>>
>> Don't worry -- there's no Academie Anglaise :-)
> I am not French, only my wife is;), but it is a funny remark.
>>
>>> But seriously there is just no need to pay the cost of the
>>> construction of another String / Array.
>>> Performance difference is already enormous for moderately long strings :
>>
>> It depends, though; sometimes you might want a copy, sometimes you
>> might definitely not. So the + vs. << decision may not be premature,
>> and the right decision may not even be the optimizing one :-)
> Hmm David when one does
> a += b
> the copy is thrown away and you have the same semantics (save some
> implicit calls to to_s) as for
> a << b

They're not interchangeable, though:

a = "Hello"
b = " there"
c = a

a += b
puts a        # Hello there
puts c        # Hello

a = "Hello"
c = a
a << b
puts a        # Hello there
puts c        # Hello there


David

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