Yes, thanks, but then I can't pass a string or int as a parameter as
well, which is what a want.
Neil Kimber wrote:
> You're not passing by reference.
> Change:
>
> function add($child) {
> $this->children[] = $child;
> }
>
> to
>
> function add(&$child) {
> $this->children[] = &$child;
> }
>
> This should work. When you pass an object as a parameter PHP makes a copy of
> that object as a local instance in your method. So, your original code:
>
> 4 $obj2->add(", something else");
> 5 $obj1->add($obj2);
>
> would alter $obj2 and store a copy of that altered object in $obj1. But,
>
> 5 $obj1->add($obj2);
> 4 $obj2->add(", something else");
>
> would store a copy of unaltered $obj2 in $obj1. You'd then alter a different
> instance of $obj2 in the succeeding line.
> By using the suggested altered code at the top of this email, line 5 would
> not pass a copy but would pass a reference to the actual instance of the
> object. Note, you also have to ensure that you store a reference to this guy
> in your array as by default adding items to arrays causes copies to be made.
> So you also need the line:
>
> $this->children[] = &$child;
>
> Hope this helps.
>
>
>
>>-----Original Message-----
>>From: Brian White [mailto:[EMAIL PROTECTED]]
>>Sent: 17 October 2001 04:41
>>To: SafeV; [EMAIL PROTECTED]
>>Subject: Re: [PHP] Object and reference problem
>>
>>
>>I think you are going to have to live with it.
>>
>>Functional overloading only really makes sense in strongly typed
>>languages, and I bet is a bugger to implement in a name based
>>scripting language so I don't think you are goign to get it.
>>
>>What I have sometimes wished for was that all objects and arrays
>>were passed around as pointers by default, with the ability
>>to create a copy when required, but that is such a fundamental
>>change that I doubt if it will happen, and there are probably
>>goo reasons not to ( have I ever told people how much I like
>>Python ... )
>>
>>Maybe you are just going to have to bite the bullet and have
>>an "AddRef" method......
>>
>>
>>At 04:28 17/10/2001 +0200, SafeV wrote:
>>
>>>Someone, have a go at this!
>>>
>>>I have encountered a very troublesome problem, which I don't see how to
>>>solve in an elegant way, since PHP doesn't support method overloading.
>>>
>>>Suppose my class is, kind of a tree, like:
>>>
>>>class A {
>>> var $children;
>>>
>>> function A() {
>>> $this->children = array();
>>> }
>>>
>>> // I want this to accept both objects and strings etc.
>>> // IE. mixed
>>> function add($child) {
>>> $this->children[] = $child;
>>> }
>>>
>>> function printStuff() {
>>> foreach ($this->children as $child) {
>>> if (is_object($child))
>>> $child->printStuff();
>>> else
>>> echo $child;
>>> }
>>> }
>>>}
>>>
>>>Now this is fine:
>>>
>>>1 $obj1 = new A();
>>>2 $obj2 = new A();
>>>3 $obj1->add("Something");
>>>4 $obj2->add(", something else");
>>>5 $obj1->add($obj2);
>>>6 $obj1->printStuff();
>>>
>>>and prints out "something, something else"
>>>
>>>But if I swap lines 4 and 5 it only prints out "something".
>>>Obviously, the add method of $obj1 only receives a copy of $obj2, and
>>>if I try to add something to $obj2 afterwards, even thought it's
>>>
>>supposed
>>
>>>to be hooked with $obj1, it will "disappear".
>>>
>>>For objects only I could solve this with declaring add() like:
>>>function add(&$child) {
>>> $this->children[] = $child;
>>>}
>>>So it receives a reference of the object, but then I can't add a string
>>>(fatal error, cannot pass string as reference), or an integer or double,
>>>for that matter! And I really don't want to use different method names!
>>>
>>>I don't have full control over the reference stuff in PHP, does anyone
>>>know how I can fix this? Or a workaround?
>>>
>>>Thanx!
>>>
>>>
>>>--
>>>PHP General Mailing List (http://www.php.net/)
>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>>For additional commands, e-mail: [EMAIL PROTECTED]
>>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>>>
>>-------------------------
>>Brian White
>>Step Two Designs Pty Ltd - SGML, XML & HTML Consultancy
>>Phone: +612-93197901
>>Web: http://www.steptwo.com.au/
>>Email: [EMAIL PROTECTED]
>>
>>
>>--
>>PHP General Mailing List (http://www.php.net/)
>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>For additional commands, e-mail: [EMAIL PROTECTED]
>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>>
>
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