I am new to php. I have a website were i want to show data's in different pages. I have come across lots of pagination script ( eg http://www.tonymarston.net/php-mysql/pagination.html). In this website he is given isset($_GET['pageno']) in his script. I know that its for total no of pages, but how its done in the first place..its confusing and can any one please explain.
Thanks in advance
You should look up HTTP requests and what they mean.
http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol
The most common one is GET. Which is any typical URL request. If you click on the above link, you are submitting a GET request. So if you add a parameter to that URL.. lets say..
http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol?pageno=2
...then the page that is executed by your GET will have the pageno parameter in it's GET scope with the value of 2. The way that is retrieve in PHP is
var $page = $_GET['pageno'];
$_GET is a global reserved variable in PH. As is $_POST - another common HTTP Request.
isset() simply asks the question whether a variable has been assigned .. or "is set".
http://php.net/manual/en/function.isset.php
http://php.net/manual/en/reserved.variables.get.php
http://php.net/manual/en/reserved.variables.post.php
He doessng gives isset($_GET['pageno']), but $_GET['pageno']. The first time the $_GET['pageno'] is not set, so $pageno = 1 :
if (isset($_GET['pageno'])) { // if there is anything set in $_GET['pageno']
$pageno = $_GET['pageno']; // $pageno whoult be the value in $_GET['pageno']
} else {
$pageno = 1; // nothing is set in $_GET['pageno'], so $pageno is 1
} // if
