What should we use object scope like "--->" in PHP?

Question

I am following through this tutorial

http://www.1stwebdesigner.com/tutorials/infinite-scrolling-tutorial/

And it contains this code snippet:

<!--?php 
$con = mysql_connect("localhost", "username", "password"); 
mysql_select_db("database_name"); 
$result = mysql_query("select SQL_CALC_FOUND_ROWS * from scroll_images order by id asc   limit 12"); 
$row_object = mysql_query("Select Found_Rows() as rowcount"); 
$row_object = mysql_fetch_object($row_object); 
$actual_row_count = $row_object--->rowcount;
?>

The line $actual_row_count = $row_object--->rowcount; confuses me, what is --->rowcount supposed to do? When I have it in my PHP, I receive errors.

<?php
$sql_fetch = "SELECT * FROM articles ORDER BY time DESC limit 4;";
$dbresult = mysqli_query( $db, $sql_fetch );

$row_object = mysqli_query( $db, "Select Found_Rows() as rowcount" );
$row_object = mysqli_fetch_object( $row_object );
$actual_row_count = $row_object--->rowcount;
?>

Parse error: syntax error, unexpected T_OBJECT_OPERATOR in /Applications/MAMP/htdocs/index.php on line 14

It looks like an HTML comment. – nickb Jul 09 '13 at 13:45 — nickb, Jul 09 '13 at 13:45
It's a poorly formatted HTML code. – BenM Jul 09 '13 at 13:45 — BenM, Jul 09 '13 at 13:45
@nickb it is. This would give a syntax error. – Brewal Jul 09 '13 at 13:46 — Brewal, Jul 09 '13 at 13:46
It's an outdated and poorly formatted tutorial. – j08691 Jul 09 '13 at 13:46 — j08691, Jul 09 '13 at 13:46
The funny thing is that tutorial is only a year old. – Steven Jul 09 '13 at 13:53 — Steven, Jul 09 '13 at 13:53

score 5 · Accepted Answer · edited May 25 '19 at 11:48

 is the way you comment out things in HTML. That line is indeed not correct (stop reading the article this instant).

I would imagine that he meant

<?php 
$con = mysql_connect("localhost", "username", "password"); 
mysql_select_db("database_name"); 
$result = mysql_query("select SQL_CALC_FOUND_ROWS * from scroll_images order by id asc   limit 12"); 
$row_object = mysql_query("Select Found_Rows() as rowcount"); 
$row_object = mysql_fetch_object($row_object); 
$actual_row_count = $row_object->rowcount;
?>

On a different note:

Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.

score 2 · Answer 2 · answered Jul 09 '13 at 13:46

2

I imagine it is suppose to be

$actual_row_count = $row_object->rowcount;

But that's not how you get the number of rows for mysqli.

So what ever that code is, it is pretty much 100% wrong.

answered Jul 09 '13 at 13:46

Steven

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score 1 · Answer 3 · answered Jul 09 '13 at 13:47

1

It is just a mistake. Replace rowcount; with $row_object->rowcount;

answered Jul 09 '13 at 13:47

Voitcus

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ddavison · Answer 4 · 2013-07-09T13:58:37.657

1

---> is not an actual operator. The actual operator you need is -> lamely called, the "arrow operator", or T_OBJECT_OPERATOR.

Evaluating that php would result in -

$actual_row_count = $rowobject-- (which means decrement by 1)->rowcount;

which is not correct PHP as you can only use the arrow operator on an object, not an integer, which is what the "$rowobject--" would evaluate to. This explains your unexpected "T_OBJECT_OPERATOR".

What you are experiencing is poor php engineering. Change it to

$actual_row_count = $rowobject->rowcount

and your PHP will be set. Refer to other answers for the rest

edited Jul 09 '13 at 13:58

answered Jul 09 '13 at 13:47

ddavison

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php doesn't work that way. You can't `$rowobject-- ->rowcount;` So where ever that code is from, it's just 100% wrong. And to top it all off, you can't decrement by 1 an object, and `$rowobject` is an object. – Steven Jul 09 '13 at 13:49
You're absolutely correct. hopefully i got that across in my answer – ddavison Jul 09 '13 at 13:52

score 1 · Answer 5 · answered Jul 09 '13 at 13:48

1

---> itself doenst do anything.
--> is used to close HTML comment (that you start on row1 with
-> is used to get the instance of an object (in your case, $row_object->rowcount)

answered Jul 09 '13 at 13:48

Pokepoke

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Actually, `--->` is a valid way of closing an HTML comment (because it ends with `-->`. – Madara's Ghost Jul 09 '13 at 13:48
Therefore he wrote 'itself', i guess. – Wottensprels Jul 09 '13 at 13:50

score 0 · Answer 6 · answered Jul 09 '13 at 13:46

0

It's trying to get an instance of an object, just not correctly. Try this instead:

$row_object->rowcount

answered Jul 09 '13 at 13:46

Casper André Casse

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score 0 · Answer 7 · answered Jul 09 '13 at 13:52

0

Its just wrong by user instead of

$rowobject--->rowcount;

Replace to

$rowobject->rowcount

answered Jul 09 '13 at 13:52

Bikash Nayak

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What should we use object scope like "--->" in PHP?

7 Answers7