Passing arrays as url parameter

Question

What is the best way that I can pass an array as a url parameter? I was thinking if this is possible:

$aValues = array();

$url = \'http://www.example.com?a         


        

Answer 1

Easiest way would be to use the serialize function.

It serializes any variable for storage or transfer. You can read about it in the php manual - serialize

The variable can be restored by using unserialize

So in the passing to the URL you use:

$url = urlencode(serialize($array))

and to restore the variable you use

$var = unserialize(urldecode($_GET['array']))

Be careful here though. The maximum size of a GET request is limited to 4k, which you can easily exceed by passing arrays in a URL.

Also, its really not quite the safest way to pass data! You should probably look into using sessions instead.

Answer 2

There is a very simple solution: http_build_query(). It takes your query parameters as an associative array:

$data = array(
    1,
    4,
    'a' => 'b',
    'c' => 'd'
);
$query = http_build_query(array('aParam' => $data));

will return

string(63) "aParam%5B0%5D=1&aParam%5B1%5D=4&aParam%5Ba%5D=b&aParam%5Bc%5D=d"

http_build_query() handles all the necessary escaping for you (%5B => [ and %5D => ]), so this string is equal to aParam[0]=1&aParam[1]=4&aParam[a]=b&aParam[c]=d.

Answer 3

please escape your variables when outputting (urlencode).

and you can’t just print an array, you have to build your url using a loop in some way

$url = 'http://example.com/index.php?'
$first = true;
foreach($aValues as $key => $value) {
  if(!$first) $url .= '&amp';
  else $first = false;
  $url .= 'aValues['.urlencode($key).']='.urlencode($value);
}

Answer 4

 <?php
$array["a"] = "Thusitha";
$array["b"] = "Sumanadasa";
$array["c"] = "Lakmal";
$array["d"] = "Nanayakkara";

$str = serialize($array);
$strenc = urlencode($str);
print $str . "\n";
print $strenc . "\n";
?> 

print $str . "\n"; gives a:4:{s:1:"a";s:8:"Thusitha";s:1:"b";s:10:"Sumanadasa";s:1:"c";s:6:"Lakmal";s:1:"d";s:11:"Nanayakkara";} and

print $strenc . "\n"; gives

a%3A4%3A%7Bs%3A1%3A%22a%22%3Bs%3A8%3A%22Thusitha%22%3Bs%3A1%3A%22b%22%3Bs%3A10%3A%22Sumanadasa%22%3Bs%3A1%3A%22c%22%3Bs%3A6%3A%22Lakmal%22%3Bs%3A1%3A%22d%22%3Bs%3A11%3A%22Nanayakkara%22%3B%7D

So if you want to pass this $array through URL to page_no_2.php,

ex:-

$url ='http://page_no_2.php?data=".$strenc."';

To return back to the original array, it needs to be urldecode(), then unserialize(), like this in page_no_2.php:

    <?php
    $strenc2= $_GET['data'];
    $arr = unserialize(urldecode($strenc2));
    var_dump($arr);
    ?>

gives

 array(4) {
  ["a"]=>
  string(8) "Thusitha"
  ["b"]=>
  string(10) "Sumanadasa"
  ["c"]=>
  string(6) "Lakmal"
  ["d"]=>
  string(11) "Nanayakkara"
}

again :D