recursivity with objects

[pepete]

Hi,

I am trying to do a script that is must print a tree of object (my
objects are some comments).

For more details, a "comment" is an object which can be at the top of
the tree (father), or which can be an answer to another comment
(children). There is no limit in father-children relation (a father can
have children, which can have children, which ...).

I have made 2 object, the comment and a comment contener (just an
array). Un comment is simply composed with a texte and an id.

Here is the code and my test failure.

I want to display the tree (commen id):
1->4
->5->7->8->9
->6
2->
3->

Explain : commen 1 has 3 answers (4-5-6), 2 & 3 have not answer. Comment
5 has one answer (7) which has one answer(8) ...

/*------------------------------------------*/
<?php
classe comments
{//contener

//comments array
var $tab_comments;

function comments()
{//constructor
$this->tab_comments=a rray();
}

function addcomment($com ment)
{//add a comment into the array
$this->tab_comments[]=$comment;
}
}//end comments

class comment
{//the comment
var $id;
var $contenu;

//children array
var $tab_comments;

function comment($num, $texte)
{//constructor
$this->id=$num;
$this->contenu=$texte ;
$this->tab_comments=a rray();
}

function outprint()
{
echo "I am comment number {$this->id}<br>";
$this->printFils();
}

function printFils()
{ //print all children
foreach ($this->tab_comments as $comment)
{
$comment->outprint();
}
}

function addcomment($com ment)
{//add a children
$this->tab_comments[]=$comment;
}
}//fin classe comment

//Here is the test
//contener
$commentaires=n ew comments();

//comments
$commentaire1=n ew comment('1','co mmentaire 1');
$commentaire2=n ew comment('2','co mmentaire 2');
$commentaire3=n ew comment('3','co mmentaire 3');
$commentaire4=n ew comment('4','co mmentaire 4');
$commentaire5=n ew comment('5','co mmentaire 5');
$commentaire6=n ew comment('6','co mmentaire 6');
$commentaire7=n ew comment('7','co mmentaire 7');
$commentaire8=n ew comment('8','co mmentaire 8');
$commentaire9=n ew comment('9','co mmentaire 9');

//tree
//add fathers to contener
$commentaires->addcomment($co mmentaire1);
$commentaires->addcomment($co mmentaire2);
$commentaires->addcomment($co mmentaire3);

//children-father relationship
$commentaire1->addcomment($co mmentaire4);
$commentaire1->addcomment($co mmentaire5);
$commentaire1->addcomment($co mmentaire6);

$commentaire5->addcomment($co mmentaire7);
$commentaire5->addcomment($co mmentaire8);
$commentaire5->addcomment($co mmentaire9);

//Display $commentaire1
$commentaire1->outprint();

/* end test */
?>

The result is :
I am comment number 1
I am comment number 4
I am comment number 5
I am comment number 6


This mean that the tree is not completly read and that I need help !!

Best regards

Pepete

[Zurab Davitiani]

Re: recursivity with objects

pepete wrote:

<snip>
[color=blue]
> //tree
> //add fathers to contener
> $commentaires->addcomment($co mmentaire1);
> $commentaires->addcomment($co mmentaire2);
> $commentaires->addcomment($co mmentaire3);
>
> //children-father relationship
> $commentaire1->addcomment($co mmentaire4);
> $commentaire1->addcomment($co mmentaire5);
> $commentaire1->addcomment($co mmentaire6);
>
> $commentaire5->addcomment($co mmentaire7);
> $commentaire5->addcomment($co mmentaire8);
> $commentaire5->addcomment($co mmentaire9);
>
> //Display $commentaire1
> $commentaire1->outprint();
>
> /* end test */
> ?>
>
> The result is :
> I am comment number 1
> I am comment number 4
> I am comment number 5
> I am comment number 6
>
>
> This mean that the tree is not completly read and that I need help !![/color]

If you are using PHP4, this is because PHP4 passes values, not references by
default. You can fix this by modifying the the addcomment method definition
with a reference argument.

So, the way you have it now, when you add $commentaire5 to $commentaire1, a
copy of $commentaire5 is made. Any further changes to $commentaire5 are
made to the original variable, and not to the copy held by $commentaire1.

Your updated function definition should look like:

function addcomment(&$co mment) {...}

Read info about references on PHP website:

http://www.php.net/manual/en/language.references.php

http://www.php.net/manual/en/language.references.pass.php