Question on "reference"

[rolwong]

class myclass {
function myclass($v) {
global $ref;
$ref[] = &$this;
$this->set($v);
}
function get() {
print "Value : {$this->var}<br>";
}
function set($v) {
$this->var = $v;
}
}
$a = new myclass(1); ...(1)
$b =& new myclass(1); ...(2)
$a->get();
$b->get();
print_r($ref);
$a->set(2);
$b->set(2);
$a->get();
$b->get();
print_r($ref);

I am new in passing by reference. I have difficulty in understanding the above code. Why only $b can reference to myclass. In my understand, when $a is created by "new" statment. The constructor would be executed. Then $ref[] = &$this; $ref[0] would then reference to $a. But in fact it is not, $a and $ref[0] are separate copy and there is no reference between them. Did I make any mistake in my understanding?

Thanks.

[planetsim]

Im a little bit curious as to why you are referencing $this.

I think you have misunderstood references you may wish to read up on them again http://www.php.net/manual/en/language.references.php

[Shrike]

That's a little odd. The principle works in PHP 5, so I guess it's something that Zend have known about. I suspect it's something to do with creating a reference using $this.

[Shrike]

To elaborate a little, the 'correct' way to pass by reference in PHP 4 would be

$a = null;

class a 
{
	var $a = 0;

function a()
{
	//
}

function b()
{
	$this->a = 1;
}

function c()
{
	echo $this->a . "<br>";
}
}

$obj = new a; // New object
echo $obj->c(); // Call get method
$a =& $obj; // Create reference
$a->b(); // Call set method on reference
echo $obj->c(); // Call get method again

Creating references inside of a class is likely to cause a headache in the end, no?