Re: Question about internal workings of references/variables.

On Wed, 10 Mar 2004, Robert Cummings wrote: > 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? yes, that is true and called "copy-on-write". It's done for all types of variables though. > 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? Never tried that myself, but I believe it to be true. > > Last but not least, do objects work under the same principles? yes, in php 4 they do. in php 5 it is true for "object-handles" and not objects, but that shouldn't be of any concern. regards, Derick