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Date: 10 Mar 2004 10:24:00 -0500
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Subject: Question about internal workings of references/variables.
From: robert@interjinn.com (Robert Cummings)

Hi Internals,

I'd like to confirm/refute some knowledge I think I have of the PHP
internal workings with respect to variables and references. I believe
that when a variable is assigned the value of another variable an
internal reference is created and some bit is used to keep track of
whether the value should be copied when an attempt is made to change
either the original variable or the newly assigned variable (maybe this
isn't the case for integers or floats since the performance would be
similar). Can anyone confirm or elaborate further?

Also I think I remember hearing once upon a time that creating a
reference in PHP script is more work than creating a copy when the copy
won't be altered? Can this be confirmed also?

Last but not least, do objects work under the same principles?

I did some benchmarking and my first question seems to hold since
assigning by value a 100000 entry array 10 million times runs as fast as
assigning a single integer 10 million times.

The second doesn't seem to hold true since the execution time is
slightly (but significantly and consistently) faster.

Thanks for any information.

Rob.
-- 
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