Strip off specific parameter from URL's querystring

Question

I have some links in a Powerpoint presentation, and for some reason, when those links get clicked, it adds a return parameter to the URL. Well, that return parameter is causing my Joomla site's MVC pattern to get bungled.

What's an efficient way to strip off this return parameter using PHP?

Example: http://mydomain.example/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0

possible duplicate of [Beautiful way to remove GET-variables with PHP?](http://stackoverflow.com/questions/1251582/beautiful-way-to-remove-get-variables-with-php) — PiTheNumber, Mar 05 '13 at 12:17

score 115 · Accepted Answer · edited Aug 14 '15 at 15:07

115

The safest "correct" method would be:

Parse the url into an array with parse_url()
Extract the query portion, decompose that into an array using parse_str()
Delete the query parameters you want by unset() them from the array
Rebuild the original url using http_build_query()

Quick and dirty is to use a string search/replace and/or regex to kill off the value.

edited Aug 14 '15 at 15:07

Tamlyn

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answered Feb 08 '11 at 19:45

Marc B

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mmm weird, my `$parsedurl['query']` is a single string containing all params – ajax333221 Apr 10 '14 at 03:01
example: http://stackoverflow.com/questions/1251582/beautiful-way-to-remove-get-variables-with-php/1251597#1251597 – Ari Sep 01 '15 at 01:34
1

can you give an example of scenario in which the dirty regex would fail ? – Vincent Apr 25 '20 at 05:13
2

Please give an example? – Jones G Nov 14 '20 at 08:39
2

parse_url() is buggy. It is not safe to use it at all. – holden321 Jan 07 '22 at 19:04
1

[Implementation](https://stackoverflow.com/questions/4937478/strip-off-url-parameter-with-php/71202513#71202513) – Whip Feb 21 '22 at 07:22

score 93 · Answer 2 · edited May 23 '17 at 12:34

93

In a different thread Justin suggests that the fastest way is to use strtok()

 $url = strtok($url, '?');

See his full answer with speed tests as well here: https://stackoverflow.com/a/1251650/452515

edited May 23 '17 at 12:34

Community

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answered Aug 07 '12 at 12:41

Lars Koudal

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The question was how to remove the specific GET variable `return` and not to remove all GET variables. – mgutt Jan 17 '20 at 08:57

score 35 · Answer 3 · edited Jun 18 '22 at 09:19

35

This is to complement Marc B's answer with an example, while it may look quite long, it's a safe way to remove a parameter. In this example we remove page_number

<?php
$x = 'http://url.example/search/?location=london&page_number=1';

$parsed = parse_url($x);
$query = $parsed['query'];

parse_str($query, $params);

unset($params['page_number']);
$string = http_build_query($params);
var_dump($string);

edited Jun 18 '22 at 09:19

Stephen Ostermiller

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answered Dec 29 '14 at 13:25

Sergey Telshevsky

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Thank you Sergey, and thank you @Marc B, brilliant help. – luke_mclachlan Mar 06 '15 at 14:52
3

Comment for anyone who finds themselves using this code that this just returns the query string (minus the parameter you've stripped out.) You won't have a full url any more, if that's what you want. – Codemonkey Nov 15 '18 at 18:00

score 17 · Answer 4 · answered Nov 18 '13 at 14:05

17

function removeParam($url, $param) {
    $url = preg_replace('/(&|\?)'.preg_quote($param).'=[^&]*$/', '', $url);
    $url = preg_replace('/(&|\?)'.preg_quote($param).'=[^&]*&/', '$1', $url);
    return $url;
}

answered Nov 18 '13 at 14:05

kraftb

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Agreed, exactly what I was looking for. regex is my weakness, but I knew it was the answer I needed. – ctrlbrk Apr 27 '20 at 22:50
If the url has a #hash at the end following the target parameter, this function will strip it off as well. Careful what you copy / paste, this answer has been out there for 8 years on a question with 150k views and no one has noticed. – Maciej Krawczyk Feb 10 '22 at 11:21
Hmm, it seems like most of the answers here will strip out the hash. – Maciej Krawczyk Feb 10 '22 at 11:37

NikiC · Answer 5 · 2011-02-08T19:51:46.030

14

parse_str($queryString, $vars);
unset($vars['return']);
$queryString = http_build_query($vars);

parse_str parses a query string, http_build_query creates a query string.

edited Feb 08 '11 at 19:51

answered Feb 08 '11 at 19:46

NikiC

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score 12 · Answer 6 · edited Jan 18 '23 at 10:57

Procedural Implementation of Marc B's Answer after refining Sergey Telshevsky's Answer.

function strip_param_from_url($url, $param)
{
    $base_url = strtok($url, '?');                   // Get the base URL
    $parsed_url = parse_url($url);                   // Parse it
                               // Add missing {
    if(array_key_exists('query',$parsed_url)) {      // Only execute if there are parameters
        $query = $parsed_url['query'];               // Get the query string
        parse_str($query, $parameters);              // Convert Parameters into array
        unset($parameters[$param]);                  // Delete the one you want
        $new_query = http_build_query($parameters);  // Rebuilt query string
        $url =$base_url.'?'.$new_query;              // Finally URL is ready
    }
    return $url;            
}

// Usage
echo strip_param_from_url( 'http://url.example/search/?location=london&page_number=1', 'location' )

It also leaves the '?' which could cause a problem later down the line — Chris Pink, Jul 04 '23 at 17:28

score 9 · Answer 7 · answered Feb 08 '11 at 19:42

9

You could do a preg_replace like:

$new_url = preg_replace('/&?return=[^&]*/', '', $old_url);

answered Feb 08 '11 at 19:42

Aaron Hathaway

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Not a good idea if "?return=" is not the last parameter. A query like "urlerror.com/index.php?return=1&test=abc" would get changed to "urlerror.com/index.php&test=abc" – kraftb Nov 18 '13 at 13:54
preg_replace('/return=[^&]?&?/i', '', $_SERVER['REQUEST_URI']); – Chris Greenwood May 27 '14 at 16:32
This answer is wrong. Analysis: https://stackoverflow.com/a/47527628/318765 – mgutt Nov 28 '17 at 09:33

doublejosh · Answer 8 · 2013-09-14T22:41:57.083

Here is the actual code for what's described above as the "the safest 'correct' method"...

function reduce_query($uri = '') {
    $kill_params = array('gclid');

    $uri_array = parse_url($uri);
    if (isset($uri_array['query'])) {
        // Do the chopping.
        $params = array();
        foreach (explode('&', $uri_array['query']) as $param) {
          $item = explode('=', $param);
          if (!in_array($item[0], $kill_params)) {
            $params[$item[0]] = isset($item[1]) ? $item[1] : '';
          }
        }
        // Sort the parameter array to maximize cache hits.
        ksort($params);
        // Build new URL (no hosts, domains, or fragments involved).
        $new_uri = '';
        if ($uri_array['path']) {
          $new_uri = $uri_array['path'];
        }
        if (count($params) > 0) {
          // Wish there was a more elegant option.
          $new_uri .= '?' . urldecode(http_build_query($params));
        }
        return $new_uri;
    }
    return $uri;
}

$_SERVER['REQUEST_URI'] = reduce_query($_SERVER['REQUEST_URI']);

However, since this will likely exist prior to the bootstrap of your application, you should probably put it into an anonymous function. Like this...

call_user_func(function($uri) {
    $kill_params = array('gclid');

    $uri_array = parse_url($uri);
    if (isset($uri_array['query'])) {
        // Do the chopping.
        $params = array();
        foreach (explode('&', $uri_array['query']) as $param) {
          $item = explode('=', $param);
          if (!in_array($item[0], $kill_params)) {
            $params[$item[0]] = isset($item[1]) ? $item[1] : '';
          }
        }
        // Sort the parameter array to maximize cache hits.
        ksort($params);
        // Build new URL (no hosts, domains, or fragments involved).
        $new_uri = '';
        if ($uri_array['path']) {
          $new_uri = $uri_array['path'];
        }
        if (count($params) > 0) {
          // Wish there was a more elegant option.
          $new_uri .= '?' . urldecode(http_build_query($params));
        }
        // Update server variable.
        $_SERVER['REQUEST_URI'] = $new_uri;

    }
}, $_SERVER['REQUEST_URI']);

NOTE: Updated with urldecode() to avoid double encoding via http_build_query() function. NOTE: Updated with ksort() to allow params with no value without an error.

Great examples! Note to others: the 'gclid' in the $kill_params array is what will be removed from the query string portion of the uri. Note also that this method of rebuilding the url may not be complete. Also, I have just come across another approach that may work better for splitting and rejoining more modern URIs than using parse_url(); here: http://nadeausoftware.com/articles/2008/05/php_tip_how_parse_and_build_urls — Damian Green, Dec 09 '15 at 16:16

score 5 · Answer 9 · edited Jun 18 '22 at 09:21

5

This one of many ways, not tested, but should work.

$link = 'http://mydomain.example/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0';
$linkParts = explode('&return=', $link);
$link = $linkParts[0];

edited Jun 18 '22 at 09:21

Stephen Ostermiller

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answered Feb 08 '11 at 19:43

Chuck Morris

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This solution is counting for `return` to be at the last position, if that's not the case you will lose all the other params from `return` param as well. – Dr. House Nov 16 '20 at 14:24

score 4 · Answer 10 · edited May 23 '17 at 12:34

Wow, there are a lot of examples here. I am providing one that does some error handling. It rebuilds and returns the entire URL with the query-string-param-to-be-removed, removed. It also provides a bonus function that builds the current URL on the fly. Tested, works!

Credit to Mark B for the steps. This is a complete solution to tpow's "strip off this return parameter" original question -- might be handy for beginners, trying to avoid PHP gotchas. :-)

<?php

function currenturl_without_queryparam( $queryparamkey ) {
    $current_url = current_url();
    $parsed_url = parse_url( $current_url );
    if( array_key_exists( 'query', $parsed_url )) {
        $query_portion = $parsed_url['query'];
    } else {
        return $current_url;
    }

    parse_str( $query_portion, $query_array );

    if( array_key_exists( $queryparamkey , $query_array ) ) {
        unset( $query_array[$queryparamkey] );
        $q = ( count( $query_array ) === 0 ) ? '' : '?';
        return $parsed_url['scheme'] . '://' . $parsed_url['host'] . $parsed_url['path'] . $q . http_build_query( $query_array );
    } else {
        return $current_url;
    }
}

function current_url() {
    $current_url = 'http' . (isset($_SERVER['HTTPS']) ? 's' : '') . '://' . "{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
    return $current_url;
}

echo currenturl_without_queryparam( 'key' );

?>

score 4 · Answer 11 · answered Feb 08 '11 at 19:42

4

$var = preg_replace( "/return=[^&]+/", "", $var ); 
$var = preg_replace( "/&{2,}/", "&", $var );

Second line will just replace && to &

answered Feb 08 '11 at 19:42

SergeS

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Did you down vote everyone else? Not pointing fingers, but everyone has a -1 except for you... – Aaron Hathaway Feb 08 '11 at 20:12
If you click on the number of votes it will give you a break down of the votes (I think you need a higher reputation to do this). If you didn't do it, that's cool, just thought it was peculiar that everyone has a -1 except for you. – Aaron Hathaway Feb 08 '11 at 20:20
Add a 3-rd "preg_replace" to replace "?&" to "?", like: `$var = preg_replace("/\?&/", "?", $var);` – Vadzym Mar 04 '15 at 16:08

score 3 · Answer 12 · answered Jan 18 '16 at 23:21

3

very simple

$link = "http://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0"
echo substr($link, 0, strpos($link, "return") - 1);
//output : http://example.com/index.php?id=115&Itemid=283

answered Jan 18 '16 at 23:21

Bruno Ribeiro

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mgutt · Answer 13 · 2017-11-28T09:32:29.060

@MarcB mentioned that it is dirty to use regex to remove an url parameter. And yes it is, because it's not as easy as it looks:

$urls = array(
  'example.com/?foo=bar',
  'example.com/?bar=foo&foo=bar',
  'example.com/?foo=bar&bar=foo',
);

echo 'Original' . PHP_EOL;
foreach ($urls as $url) {
  echo $url . PHP_EOL;
}

echo PHP_EOL . '@AaronHathaway' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('#&?foo=[^&]*#', null, $url) . PHP_EOL;
}

echo PHP_EOL . '@SergeS' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace( "/&{2,}/", "&", preg_replace( "/foo=[^&]+/", "", $url)) . PHP_EOL;
}

echo PHP_EOL . '@Justin' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('/([?&])foo=[^&]+(&|$)/', '$1', $url) . PHP_EOL;
}

echo PHP_EOL . '@kraftb' . PHP_EOL;
foreach ($urls as $url) {
  echo preg_replace('/(&|\?)foo=[^&]*&/', '$1', preg_replace('/(&|\?)foo=[^&]*$/', '', $url)) . PHP_EOL;
}

echo PHP_EOL . 'My version' . PHP_EOL;
foreach ($urls as $url) {
  echo str_replace('/&', '/?', preg_replace('#[&?]foo=[^&]*#', null, $url)) . PHP_EOL;
}

returns:

Original
example.com/?foo=bar
example.com/?bar=foo&foo=bar
example.com/?foo=bar&bar=foo

@AaronHathaway
example.com/?
example.com/?bar=foo
example.com/?&bar=foo

@SergeS
example.com/?
example.com/?bar=foo&
example.com/?&bar=foo

@Justin
example.com/?
example.com/?bar=foo&
example.com/?bar=foo

@kraftb
example.com/
example.com/?bar=foo
example.com/?bar=foo

My version
example.com/
example.com/?bar=foo
example.com/?bar=foo

As you can see only @kraftb posted a correct answer using regex and my version is a little bit smaller.

score 3 · Answer 14 · answered Feb 21 '22 at 07:21

3

Some of the examples posted are so extensive. This is what I use on my projects.

function removeQueryParameter($url, $param){
    list($baseUrl, $urlQuery) = explode('?', $url, 2);
    parse_str($urlQuery, $urlQueryArr);
    unset($urlQueryArr[$param]);

    if(count($urlQueryArr))
        return $baseUrl.'?'.http_build_query($urlQueryArr);
    else
        return $baseUrl;
}

answered Feb 21 '22 at 07:21

Whip

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It fails when there is no "?" in the URL. I got "Undefined offset: 1" – Luis Rodriguez Aug 24 '22 at 16:10
The function is to remove query parameter, in my case I was expecting one - always. If that's not the case for you, you can add a check for that. – Whip Aug 26 '22 at 04:04

score 2 · Answer 15 · answered Nov 08 '20 at 18:31

2

Remove Get Parameters From Current Page

<?php
$url_dir=$_SERVER['REQUEST_URI']; 

$url_dir_no_get_param= explode("?",$url_dir)[0];

echo $_SERVER['HTTP_HOST'].$url_dir_no_get_param;

answered Nov 08 '20 at 18:31

ahmed khan

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score 1 · Answer 16 · answered Nov 27 '19 at 12:28

This should do it:

public function removeQueryParam(string $url, string $param): string
{
    $parsedUrl = parse_url($url);

    if (isset($parsedUrl[$param])) {
        $baseUrl = strtok($url, '?');
        parse_str(parse_url($url)['query'], $query);
        unset($query[$param]);
        return sprintf('%s?%s',
            $baseUrl,
            http_build_query($query)
        );
    }

    return $url;
}

score 1 · Answer 17 · answered Jun 07 '21 at 10:08

Simple solution that will work for every url

With this solution $url format or parameter position doesn't matter, as an example I added another parameter and anchor at the end of $url:

https://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0&bonus=test#test2

Here is the simple solution:

$url = 'https://example.com/index.php?id=115&Itemid=283&return=aHR0cDovL2NvbW11bml0&bonus=test#test2';

$url_query_stirng = parse_url($url, PHP_URL_QUERY);
parse_str( $url_query_stirng, $url_parsed_query );
unset($url_parsed_query['return']);
$url = str_replace( $url_query_stirng, http_build_query( $url_parsed_query ), $url );

echo $url;

Final result for $url string is:

https://example.com/index.php?id=115&Itemid=283&bonus=test#test2

score 0 · Answer 18 · answered Jul 31 '14 at 11:35

function remove_attribute($url,$attribute)
 {
    $url=explode('?',$url);
    $new_parameters=false;
    if(isset($url[1]))
    {
        $params=explode('&',$url[1]);
        $new_parameters=ra($params,$attribute);
    }
    $construct_parameters=($new_parameters && $new_parameters!='' ) ? ('?'.$new_parameters):'';
    return $new_url=$url[0].$construct_parameters;
 }
 function ra($params,$attr)
    {   $attr=$attr.'=';
        $new_params=array();

        for($i=0;$i<count($params);$i++)
        {   
            $pos=strpos($params[$i],$attr);

            if($pos===false)
            $new_params[]=$params[$i];

        }
        if(count($new_params)>0)
        return implode('&',$new_params);
        else 
        return false; 
     }

//just copy the above code and just call this function like this to get new url without particular parameter

echo remove_attribute($url,'delete_params'); // gives new url without that parameter

score 0 · Answer 19 · answered Jul 19 '21 at 16:34

I know this is an old question but if you only want to remove one or few named url parameter you can use this function:

function RemoveGet_Regex($variable, $rewritten_url): string {
    $rewritten_url = preg_replace("/(\?)$/", "", preg_replace("/\?&/", "?", preg_replace("/((?<=\?)|&){$variable}=[\w]*/i", "", $rewritten_url)));
    return $rewritten_url;
}
function RemoveGet($name): void {
    $rewritten_url = "https://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
    if(is_array($name)) {
        for($i = 0; $i < count($name); $i++) {
            $rewritten_url = RemoveGet_Regex($name[$i], $rewritten_url);
            $is_set[] = isset($_GET[$name[$i]]);
        }
        $array_filtered = array_filter($is_set);
        if (!empty($array_filtered)) {
            header("Location: ".$rewritten_url);
        }
    }
    else {
        $rewritten_url = RemoveGet_Regex($name, $rewritten_url);
        if(isset($_GET[$name])) {
            header("Location: ".$rewritten_url);
        }
    }
}

In the first function preg_replace("/((?<=\?)|&){$variable}=[\w]*/i", "", $rewritten_url) will remove the get parameter, and the others will tidy it up. The second function will then redirect.

RemoveGet("id"); will remove the id=whatever from the url. The function can also work with arrays. For your example,

Remove(array("id","Item","return"));

Acnosoft · Answer 20 · 2022-05-21T11:17:28.363

To strip any parameter from the url using PHP script you need to follow this script:

 function getNewArray($array,$k){
        $dataArray = $array;
        unset($array[$k]);
        $dataArray = $array;
        return $dataArray;  
    }
    
function getFullURL(){
        return (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
    }

 

     $url = getFullURL(); 
      $url_components = parse_url($url);
      
      // Use parse_str() function to parse the
      // string passed via URL
      parse_str($url_components['query'], $params);
      print_r($params); 

    <ul>
    <?php foreach($params as $k=>$v){?>
    <?php 
    
    $newArray = getNewArray($params,$k);
    $parameters  = http_build_query($newArray);
    $newURL = $_SERVER['PHP_SELF']."?".$parameters;
     ?>
    <li><?=$v;?> <a href="<?=$newURL;?>">X</a>
    <?php }?>
    </ul>

Welcome to Stack Overflow. Code is a lot more helpful when it is accompanied by an explanation. Stack Overflow is about learning, not providing snippets to blindly copy and paste. Please [edit] your answer and explain how it answers the specific question being asked. See [answer]. — ChrisGPT was on strike, May 22 '22 at 12:24

score 0 · Answer 21 · edited Feb 26 '23 at 10:25

here is functions optimized for speed. But this functions DO NOT remove arrays like a[]=x&a[1]bb=y&a[2]=z by array name.

function removeQueryParam($query, $param)
{
    $quoted_param = preg_quote($param, '/');
    $pattern = "/(^$quoted_param=[^&]*&?)|(&$quoted_param=[^&]*)/";
    return preg_replace($pattern, '', $query);
}

function removeQueryParams($query, array $params)
{
    if ($params)
    {
        $pattern = '/';
        foreach ($params as $param)
        {
            $quoted_param = preg_quote($param, '/');
            $pattern .= "(^$quoted_param=[^&]*&?)|(&$quoted_param=[^&]*)|";
        }
        $pattern[-1] = '/';
        return preg_replace($pattern, '', $query);  
    }
    return $query;
}

score 0 · Answer 22 · answered Apr 29 '23 at 12:28

I needed to do the same thing in PHP to remove the GET element from the URL when the pagination reached page 1, so I created a function in a helper which I call every time in the main controller.

function fixPagination(){
    //check if exist page parameter and page number == 1
    if(isset($_GET['page']) && $_GET['page'] == '1'){
        //parse url
        $parseUrl = parse_url($_SERVER['REQUEST_URI']);
        parse_str($parseUrl['query'], $newParsedUrl);
        //unset the get page element and keep the other get elements, such as brand
        unset($newParsedUrl['page']);
        $newQueryString = http_build_query($newParsedUrl);
        //check if have another get elements
        if(empty($newQueryString)){
            $newFixUrl = base_url().$parseUrl['path'];
        }else{
            $newFixUrl = base_url().$parseUrl['path'].'?'.$newQueryString;
        }
        //redirect to new url with 301 code
        header("HTTP/1.1 301 Moved Permanently");
        header("Location: ".$newFixUrl);
        exit();
    }
}

score 0 · Answer 23 · answered Jul 30 '23 at 21:31

Building on Whip's implementation of the marked solution, I added some extra options:

An option to return the base URL - if set to false it will only return the re-built query string
An option to exclude the full URL, which will use the query string alone by default.
Changed the $param to an array to be able to exclude multiple query string parameters.

function removeQueryParameters($params = array(), $returnBaseURL = false, $url = null)
{
    $url = is_null($url) ? '?' . $_GET : $url;
    list($baseUrl, $urlQuery) = explode('?', $url, 2);
    parse_str($urlQuery, $urlQueryArr);
    foreach ($params as $param) {
        unset($urlQueryArr[$param]);
    }

    if (count($urlQueryArr)) {
        if ($returnBaseURL) {
            return $baseUrl . '?' . http_build_query($urlQueryArr);
        } else {
            return http_build_query($urlQueryArr);
        }
    } else {
        return $baseUrl;
    }
}

score -1 · Answer 24 · answered Feb 01 '17 at 02:10

-1

<? if(isset($_GET['i'])){unset($_GET['i']); header('location:/');} ?>

This will remove the 'i' parameter from the URL. Change the 'i's to whatever you need.

answered Feb 01 '17 at 02:10

Joshua Anderson

107
9

Strip off specific parameter from URL's querystring

24 Answers24

Simple solution that will work for every url

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