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

Answer 1

<!-- Comment --> 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 They are no longer maintained and are officially deprecated.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.

Answer 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.

Answer 3

It is just a mistake. Replace <!--?php with <?php and $row_object--->rowcount; with $row_object->rowcount;

Answer 4

---> 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)

Answer 5

---> 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

Answer 6

It's trying to get an instance of an object, just not correctly. Try this instead:
$row_object->rowcount

Answer 7

Its just wrong by user instead of
$rowobject--->rowcount;
Replace to
$rowobject->rowcount