[PHP] stdClass - A newbie question
Hello everybody,
In this class sketch:
?php
class Pagination {
...
public static function Pagination ($total_records, $limit, $page)
{
$total_pages = ceil($total_records / $limit);
$page = max($page, 1);
$page = min($page, $total_pages);
$offset = ($page -1) * $limit;
$pagi_obj= new stdClass;
$pagi_obj-total_pages = $total_pages;
$pagi_obj-offset = $offset;
$pagi_obj-limit = $limit;
$pagi_obj-page;
return $pagi_obj;
}
}
Why do the author used a stdClass ?
What are the advantages of using a stdClass?
Since we are already inside a class, why do we need to create a new object
from another class, inside this one?
Why do we keep the values passed as params on method Pagination inside this
stdClass object, and not inside Pagination own properties for example?
Any help clarifying this, knowing that I'm a newbie,
Regards,
Márcio
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AW: [PHP] stdClass - A newbie question
Hello Márcio,
stdClass is simply an empty class, without any properties or methods.
The object in the code sample is used to return multiple values at once. He
could also have used an associative array to achieve that, but by choosing an
object, he shows his affinity to the object oriented programming style.
The empty stdClass has the advantage of being a blank class. You can assign
new properties or methods without minding about properties and methods that
already exist in the class.
Besides that, it also doesn't use much memory. (Don't see that as performance
boosting tip! There are much better ways to do that. Besides that,
comprehensible design performance.)
By the way, there are many reasons for creating objects inside of other
objects. This should not be considered an exception. I don't know where this
code belongs to, so I can't clear out if it is good or bad OOP style.
Just think about everything in classes and objects - even return values or
other things, that you would normally consider as volatile. (eg. a network
connection)
Have a nice day,
Alex
Austrian Optic Technologies GmbH
Eisgrubengasse 2-6, A-2334 Vösendorf/Austria
Firmenbuch Nr.: FN 93629s
Firmenbuchgericht: Landesgericht Wien
UID-NR.: ATU 14976908
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Von: MEM [mailto:tal...@gmail.com]
Gesendet: Donnerstag, 30. Juli 2009 12:21
An: php-general@lists.php.net
Betreff: [PHP] stdClass - A newbie question
Hello everybody,
In this class sketch:
?php
class Pagination {
...
public static function Pagination ($total_records, $limit, $page)
{
$total_pages = ceil($total_records / $limit);
$page = max($page, 1);
$page = min($page, $total_pages);
$offset = ($page -1) * $limit;
$pagi_obj= new stdClass;
$pagi_obj-total_pages = $total_pages;
$pagi_obj-offset = $offset;
$pagi_obj-limit = $limit;
$pagi_obj-page;
return $pagi_obj;
}
}
Why do the author used a stdClass ?
What are the advantages of using a stdClass?
Since we are already inside a class, why do we need to create a new object
from another class, inside this one?
Why do we keep the values passed as params on method Pagination inside this
stdClass object, and not inside Pagination own properties for example?
Any help clarifying this, knowing that I'm a newbie,
Regards,
Márcio
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To unsubscribe, visit: http://www.php.net/unsub.php
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RE: [PHP] stdClass - A newbie question
By the way, there are many reasons for creating objects inside of other
objects. This should not be considered an exception. I don't know where
this code belongs to, so I can't clear out if it is good or bad OOP
style.
I do not intend to public judge the author, but the original article is here,
just for proper credit:
http://www.phpro.org/tutorials/Pagination-with-PHP-and-PDO.html
Just think about everything in classes and objects - even return values
or other things, that you would normally consider as volatile. (eg. a
network connection)
It would be a nice exercise to practice. :) Thanks for the tip.
And thanks a lot for the reply, I'm almost there... one last newbie question:
When we have something like this:
Class Pagination
{
Public static function Pagination ($limit, $total_records, $page)
{
$pagi_obj= new stdClass;
$pagi_obj-total_pages = $total_pages;
$pagi_obj-offset = $offset;
$pagi_obj-limit = $limit;
$pagi_obj-page = $page;
return $pagi_obj;
...
How can we, later, have something like this, for example:
$pagination_obj=Pagination::Pagination(some params)
$pagination_obj-offset;
?
I mean:
When we instantiate the class by doing:
$pagination_obj=Pagination::Pagination(some params)
We will have an object ($pagi_obj) returned where the properties of that object
will be *referring* to the values passed on the method argument, right?
How does those $pagi_obj properties, can then be accessible by doing
$pagination_obj-offset; ? I mean, they are attributes of our stdClass object
(aka pagi_obj), and they are not attributes of our Pagination class, or are
they?
Thanks in advance,
Márcio
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Re: [PHP] stdClass - A newbie question
MEM wrote:
By the way, there are many reasons for creating objects inside of other
objects. This should not be considered an exception. I don't know where
this code belongs to, so I can't clear out if it is good or bad OOP
style.
I do not intend to public judge the author, but the original article is here,
just for proper credit:
http://www.phpro.org/tutorials/Pagination-with-PHP-and-PDO.html
Just think about everything in classes and objects - even return values
or other things, that you would normally consider as volatile. (eg. a
network connection)
It would be a nice exercise to practice. :) Thanks for the tip.
And thanks a lot for the reply, I'm almost there... one last newbie question:
When we have something like this:
Class Pagination
{
Public static function Pagination ($limit, $total_records, $page)
{
$pagi_obj= new stdClass;
$pagi_obj-total_pages = $total_pages;
$pagi_obj-offset = $offset;
$pagi_obj-limit = $limit;
$pagi_obj-page = $page;
return $pagi_obj;
...
How can we, later, have something like this, for example:
$pagination_obj=Pagination::Pagination(some params)
$pagination_obj-offset;
?
I mean:
When we instantiate the class by doing:
$pagination_obj=Pagination::Pagination(some params)
Here you are calling the static method of the Pagination class which
returns the stdClass object which you are assigning to $pagination_obj.
We will have an object ($pagi_obj) returned where the properties of that
object will be *referring* to the values passed on the method argument, right?
$pagi_obj is what is was in the Pagination class, but when it was
returned you assigned it to $pagination_obj.
How does those $pagi_obj properties, can then be accessible by doing
$pagination_obj-offset; ? I mean, they are attributes of our stdClass object
(aka pagi_obj), and they are not attributes of our Pagination class, or are
they?
The Pagination class built the object for you and assigned those vars to
it. It then returned the object and you assigned it the name
$pagination_obj.
HTH
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Thanks!
-Shawn
http://www.spidean.com
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