How to get and disect the query string appended into a url? PHP

Question

I am trying to develop a PHP class which would enable me to get the query string appended into a url and process it according to the variables passed. How can this be done?

Eg

www.example.com?var1=a&var2=b&var3=c

now I want to get ?var1=a&var2=b&var3=c section and process it based on the variables.

Thanks for your responses

but I want a means by which I can get the whole query string since I wont be sure of the variable names that will be sent into the URL thus the $_GET method wont work properly.

Thanks

• Felix Kling: Are you talking about URLs with which you access your site or URLs contained in a string (from e.g. a database)?
• Stanley Ngumo: I am talking about the URLs used to access your site.

Answer 1

// Current URL: www.example.com?var1=a&var2=b&var3=c
function handleUrl()
{
 $var1 = $_GET['var1']; // now contains 'a'
 $var2 = $_GET['var2']; // now contains 'b'
 $var3 = $_GET['var3']; // now contains 'c'
 return "Querystring now contains $var1 $var2 and $var3";
}

More information at http://php.net/manual/en/reserved.variables.get.php

• ahmet2106: but dont forget to htmlspecialchars() the $_GET, because otherwise people can use xss to "hack" your site or to use it for bad things :)

Answer 2

If you want access to the URL parameters as a string you can use this:

$_SERVER['QUERY_STRING']

But, I'm not sure how that would be any more useful than $_GET. You said:

I wont be sure of the variable names

You can iterate through the $_GET array with a foreach loop:

foreach ($_GET as $key => $val) {
 echo $key . ": " . $val;
}

However... if you're talking about an arbitrary URL (not necessarily the one which was requested), then the above methods won't work since they obviously won't be in $_GET. Instead you can use parse_url

$url = 'http://username:password@hostname/path?arg=value#anchor';
print_r(parse_url($url));
echo parse_url($url, PHP_URL_QUERY);

Output:

Array
(
 [scheme] => http
 [host] => hostname
 [user] => username
 [pass] => password
 [path] => /path
 [query] => arg=value
 [fragment] => anchor
)
arg=value

• Joseph: +1 for the awesome varieties presented. This should do everything the OP requested and more. I had forgotten about a couple of the options mentioned.

Answer 3

Use $_GET

Answer 4

If you have the parameters stored in a variable, then use parse_str. Example:

$str = 'var1=a&var2=b&var3=c';
parse_str($str);
echo $var1;

Answer 5

http_build_query is the function you're probably looking for

Answer 6

Here is a minimalistic class. It should work, but it is not tested.

<?php
class URLHandler 
{
 public $get;
 public function __construct( $get );
 {
 $this->get = $get;
 }
 public function get_var( $var )
 {
 return htmlspecialchars( $this->get[$var] );
 }
 public function check_var( $var, $is )
 {
 if( $this->get_var( $var ) == $is )
 {
 return true;
 }
 else
 {
 return false;
 }
 }
}
// Below is how you can use this class
$URL = new URLHandler( $_GET );
if( $URL->check_var( 'var1', 'a' ) )
{
 echo 'yes your first var is a';
 // Here you can add a function or functions which should be loaded if var1 = a
}
else
{
 echo 'No, your first var is not a, its '.$URL->get_var( 'var2' );
 // Here you can add a function or functions which should be loaded if var1 is not a
}
if( $URL->check_var( 'var2', 'a' ) )
{
 echo 'and your second var is a';
}
else
{
 echo 'your second var is not a, its '.$URL->get_var( 'var2' );
}
?>