[development] += on arrays

Larry Garfield larry at garfieldtech.com
Wed Jan 18 01:12:38 UTC 2006

(Probable naivete on my part follows.)

So... array_merge($a, $b) favors $a, while $a += $b favors $b?  Wouldn't that 
mean that 

array_merge($a, $b) == $b += $a

Or am I just being dense? :-)

On Tuesday 17 January 2006 09:52, Karoly Negyesi wrote:
> += is not array_merge.
> array_merge overwrites keys that are the same while += does not overwrite.
> (now, that I read PHP source code, I know that $a += $a; for arrays is
> nicely optimized: the add function immediately returns and does iterate /
> copy etc the whole array needlessly.)
> In short: no, because
> >    $form['foo'] = array('a' => 'b', 'c' => 'd');
> >    $form['foo'] += array('a' => 'new b', 'e' => 'f');
> would result in array('a' => 'b', 'c' => 'd', 'e' => 'f');
> Regards
> NK

Larry Garfield			AIM: LOLG42
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