NYCPHP Meetup

[tedd]

At 9:18 AM -0400 8/19/08, David Mintz wrote:
>On Mon, Aug 18, 2008 at 11:27 PM, Daniel Convissor 
><<mailto:danielc at analysisandsolutions.com>danielc at analysisandsolutions.com> 
>wrote:
>
>  > >Does using an array reference &$array buy you anything in this instance?
>>
>>  The basic idea is you don't know how big the array is and you don't want
>>  to pass anything more than you want to.
>
>PHP functions always act on a pointer/reference of the input value UNTIL
>you write to it.  So, in this case, making $array a reference buys you
>nothing.  I don't know if it penalizes you, though.
>
>I heard somewhere that it does cost to reference/de-reference for no 
>good reason, and that if youi're not going to write to it, pass it 
>by value not reference. But I don't remember when or where, so don't 
>ask me support that with things like facts or sources.
>
>--
>David Mintz


David:

A reference is an allocation of memory and a dereference is dropping 
a segment of memory. That takes cpu time and memory to do so -- so it 
should be for a good reason.

Also, depending upon the type of memory manager used, referencing and 
dereferencing memory can fragment available memory and eventually 
cause a program to crash when the amount of memory required to 
continue is not available.

Back in my old working with Macintosh days, we seldom asked for a 
pointer, but rather a handle (a pointer to a pointer) and that 
allowed the Macintosh Memory Manager to organize/optimize available 
memory, thus Macs had less crashes than the windoze world.

Now, how php handles memory I am totally clueless -- anyone care to 
enlighten me?

Cheers,

tedd

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