http_build_query Generate URL-encoded query string stringhttp_build_query arrayformdata stringnumeric_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. 'bar', 'baz'=>'boom', 'cow'=>'milk', 'php'=>'hypertext processor'); echo http_build_query($data); // foo=bar&baz=boom&cow=milk&php=hypertext+processor ?> ]]> 'milk', 'php' =>'hypertext processor'); echo http_build_query($data); /* Outputs: 0=foo&1=bar&2=baz&3=boom&cow=milk&php=hypertext+processor */ echo http_build_query($data, 'myvar_'); /* Outputs: myvar_0=foo&myvar_1=bar&myvar_2=baz&myvar_3=boom&cow=milk&php=hypertext+processor */ ?> ]]> array('name'=>'Bob Smith', 'age'=>47, 'sex'=>'M', 'dob'=>'5/12/1956'), 'pastimes'=>array('golf', 'opera', 'poker', 'rap'), 'children'=>array('bobby'=>array('age'=>12, 'sex'=>'M'), 'sally'=>array('age'=>8, 'sex'=>'F')), 'CEO'); echo http_build_query($data, 'flags_'); ?> ]]> this will output : (word wrapped for readability) 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. foo = 'bar'; $this->baz = 'boom'; } } $data = new myClass(); echo http_build_query($data); // foo=bar&baz=boom ?> ]]> See also: parse_str, parse_url, urlencode, and array_walk