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Salathe · 12-01-2007, 02:15 AM

There's a very simple solution.

Change: (in the class2 constructor)

PHP Code:


			
$this->class1 = $class1;

To:

PHP Code:


			
$this->class1 =& $class1;

Why does this work? It's all about the way that PHP4 handles passing around references to objects. The &$class1 argument for the constructor ensured that the argument was brought in by reference, but when it was being assigned to the class1 property the assignment was by value -- a copy of the object was made and assigned to the property.

When we changed the data property, it was only changing it in the copy and not the original. Using =& the variable is assigned by reference as we intended. Hopefully you can see now why this behaviour was changed in PHP5 to assign by reference by default. :)

12-01-2007, 02:15 AM	#11 (permalink)
Salathe Moderateur Join Date: Apr 2007 Posts: 1,393 Thanks: 5	There's a very simple solution. Change: (in the class2 constructor) PHP Code: `$this->class1 = $class1;` To: PHP Code: `$this->class1 =& $class1;` Why does this work? It's all about the way that PHP4 handles passing around references to objects. The `&$class1` argument for the constructor ensured that the argument was brought in by reference, but when it was being assigned to the `class1` property the assignment was by value -- a copy of the object was made and assigned to the property. When we changed the `data` property, it was only changing it in the copy and not the original. Using `=&` the variable is assigned by reference as we intended. Hopefully you can see now why this behaviour was changed in PHP5 to assign by reference by default. :)