array of objects doesn't work

rharter

why doesn't this following work:

the following is a file with two classes, the first, an object that contains an array of objects. the second is any old object.
<?php

class Array_Of_Objects
{
var $count;
var $obj_list;

function Array_Of_Objects()
{
$this->count=0;
}

function Add_Obj($obj)
{
$this->obj_list[$this->count++] = $obj;
echo "object added, count = " . $this->count . "<br/>";
}
function Get_Obj($i)
{
return $this->obj_list[$i];
}

} //end of AOO class

class Some_Object
{
var $v;

function Some_Object($parent,$p)
  {
    $this->v = $p;
	$parent->Add_Obj($this);

  }

}

?>
I then have a debug file below. It creates the array of objects object, creates three some objects, and of course some objects insert themselves into the array of objects in its constructor. you can verify they are being inserted with a few echo statements if you like.

<?php
require_once('aoo.class');
include_once('dump.include');

$object_list = new Array_Of_Objects();

$obj1 = new Some_Object(1);
$obj2 = new Some_Object(2);
$obj3 = new Some_Object(3);

dump($object_list,"Object List");

for ($i=0; $i <3; $i++)
dump($object_list->Get_Obj($i),"Object");

?>

I then have a short function to dump the contents of objects in key value pairs:

<?php

function dump($obj,$s)
{
echo "<br/>" . $s . "<br/>";
$arr = get_object_vars($obj);
while (list($prop, $val) = each($arr))
echo "\t$prop = $val\n";
}
?>

here's the output from running the debug php:

object added, count = 1
object added, count = 1
object added, count = 1

Object List
count = 0 obj_list =
Object

Warning: Variable passed to each() is not an array or object in c:\program files\apache group\apache\htdocs\golf\dump.include on line 7

Object

Warning: Variable passed to each() is not an array or object in c:\program files\apache group\apache\htdocs\golf\dump.include on line 7

Object

Warning: Variable passed to each() is not an array or object in c:\program files\apache group\apache\htdocs\golf\dump.include on line 7
The count var : 0

I've tried this in several different ways, added debugging output to make sure what I thought should be happening was happening. It's like the array of objects and the count variables are not tied to the object life cycle ..... any insights?

Apologies for the formatting ...

victordb

I do not see a get object vars function definition anywhere in that code.

tomhath

In general you can't pass the value of $this to another object inside the constructor, it isn't completely defined until the constructor returns.

But even adding another method and calling it after the call to the constructor didn't work. The only way I could get it to add elements to the list is to call Add_Obj directly, instead of from inside Some_Object. Must be a bug somewhere in php...

$obj1 = new Some_Object(1);
$object_list->Add_Obj($obj1);

rharter

I have a much more complex example - it is very strange as all the scalar variables show up, but calling a method to return an object from the list ends up with some kind of garbage or something. Even wierder, if I dump the object directly, everything looks find, but if I try to do a Getter on an object and dump that, the object seems only partially defined ......

So I see you're a senior member, whatever that means, do you think this merits a bug report .... how in the world can you write OO code if a class can't aggregate other classes reliably!
rh

rharter

I figured it out - helps to read the section of references and the section on objects and classes in the manual 🙂

anyway, in PHP

a = b; //copies be to a, even if both b and a are objects

a =& b; // a and b now reference the same data

so, if you're used to

obja = objb; //resulting in both pointing to the same memory (data) - in PHP you have to

obja =& objb;

I'm trying to deal with this by forcing myself to think whether I want to copy the value or make sure both variables point to the same value. I think PHP passes objects by reference, so it seems to be an assignment issue ...

sorry to bother y'all,
r