PHP 5 ?

Hi,

I just bought a book about php 5 and it seems that now when you pass a variable, you pass it's adress instead of a copy of his value.

4.x -> pass value
5.0 -> pass adress

Wont that give problems if we try to run applications that were written for lower php version?

I know they always say that it should continue to work but i have a doubt about this one.
I think it might give some results we don't expect.

Thread moved from 'PHP Coding' to 'Programming Theory' by Andrew.

Reason:

I assume that you are talking about passing arguments in function calls?

To pass an argument by reference (address) you must prepend the & to the argument name in the function definition. Not doing this passes the argument by value (in all versions of PHP.)

Therefore, there is different syntax for a function definition for passing an argument by value and by reference.

Ya i know that you have to place & in front of the variable to pass it's adress in php 4 BUT it seems that now it has chanced.
In php 5 is seems you give always the adress instead of the value.
I read that you have to use the clone command now to copy a variable also to avoif that 2 variables are the same.

In php 4:
-------------------------------
$a = 1;
$b = $a;
$b = 2; // $a is still 1

In php 5:
-------------------------------
$a = 1;
$b = $a;
$b = 2; // $a is 2 now !

To get the same result as before we need to do this:

$a = 1;
$b = clone $a;
$b = 2; // $a is 1 now

I have read that in the book i just bought but as it is in dutch i can't show it to you guys but look at the following i quotes from that website:

http://www.zend.com/php5/andi-book-excerpt.php



Is that correct or is there something i missed?
And if this is true doesn't it give problems with older written programs?

This is only true for objects, not variables in general. ints, strings, etc. still behave as they always have.

Aaah ok then there wont be much problems ;)
Thanks for the info.

mmmm... i don't understand aabout to php object

check out - http://blog.libssh2.org/index.php?/archives/51-Youre-being-lied-to..html