PHP: http_build_query

Description

string http_build_query ( array formdata [, string numeric_prefix] )

Generates a URL-encoded query string from the associative (or indexed) array provided. formdata may be an array or object containing properties. A formdata array may be a simple one-dimensional structure, or an array of arrays (who in turn may contain other arrays). If numeric indices are used in the base array and a numeric_prefix is provided, it will be prepended to the numeric index for elements in the base array only. This is to allow for legal variable names when the data is decoded by PHP or another CGI application later on.

Note: arg_separator.output is used to separate arguments.

Example 1. Simple usage of http_build_query()


<?php

$data = array('foo'=>'bar',

              'baz'=>'boom',

              'cow'=>'milk',

              'php'=>'hypertext processor');

              

echo http_build_query($data); // foo=bar&baz=boom&cow=milk&php=hypertext+processor

?>

Example 2. http_build_query() with numerically index elements.


<?php

$data = array('foo', 'bar', 'baz', 'boom', 'cow' => 'milk', 'php' =>'hypertext processor');

              

echo http_build_query($data);

/* Outputs:

      0=foo&1=bar&2=baz&3=boom&cow=milk&php=hypertext+processor

 */

 

echo http_build_query($data, 'myvar_');

/* Outputs:

      myvar_0=foo&myvar_1=bar&myvar_2=baz&myvar_3=boom&cow=milk&php=hypertext+processor

 */

?>

Example 3. http_build_query() with complex arrays


<?php

$data = array('user'=>array('name'=>'Bob Smith',

                            'age'=>47,

                            'sex'=>'M',

                            'dob'=>'5/12/1956'),

              'pastimes'=>array('golf', 'opera', 'poker', 'rap'),

              'children'=>array('bobby'=>array('age'=>12,

                                               'sex'=>'M'),

                                'sally'=>array('age'=>8,

                                               'sex'=>'F')),

              'CEO');

                                               

echo http_build_query($data, 'flags_');

?>

this will output : (word wrapped for readability)

user[name]=Bob+Smith&user[age]=47&user[sex]=M&user[dob]=5%1F12%1F1956&
pastimes[0]=golf&pastimes[1]=opera&pastimes[2]=poker&pastimes[3]=rap&
children[bobby][age]=12&children[bobby][sex]=M&children[sally][age]=8&
children[sally][sex]=F&flags_0=CEO

Note: Only the numerically indexed element in the base array "CEO" received a prefix. The other numeric indices, found under pastimes, do not require a string prefix to be legal variable names.

Example 4. Using http_build_query() with an object


<?php

class myClass {

  var $foo;

  var $baz;

  

  function myClass() 

  {

    $this->foo = 'bar';

    $this->baz = 'boom';

  }

}



$data = new myClass();



echo http_build_query($data); // foo=bar&baz=boom



?>

User Contributed Notes
http_build_query

php dot net at hiddemann dot org
12-May-2005 08:22


This is a workaround for PHP versions < PHP5. It does not work with complex arrays, however.



<?



if (!function_exists('http_build_query')) {

    function http_build_query($formdata, $numeric_prefix = "")

    {

       $arr = array();

       foreach ($formdata as $key => $val)

         $arr[] = urlencode($numeric_prefix.$key)."=".urlencode($val);

       return implode($arr, "&");

    }

}



?>

aidan at php dot net
27-May-2004 10:25


This functionality is now implemented in the PEAR package PHP_Compat.



More information about using this function without upgrading your version of PHP can be found on the below link:



http://pear.php.net/package/PHP_Compat