$data = array(
  'foo'=>'bar',
  'baz'=>'boom',
  'site'=>'www.jb51.net',
  'name'=>'nowa jb51');
echo http_build_query($data);
/* output
 foo=bar&baz=boom&site=www.jb51.net&name=nowa+jb51
*/

$data = array(
  'foo',
  'bar',
  'site'=>'www.jb51.net',
  'name'=>'nowa jb51');
echo http_build_query($data);
/* output
  0=foo&1=bar&site=www.jb51.net&name=nowa+jb51
*/

$data = array(
  'foo',
  'bar',
  'site'=>'www.jb51.net',
  'name'=>'nowa jb51);
echo http_build_query($data, "nm_");
/* output
nm_0=foo&nm_1=bar&site=www.jb51.net&name=nowa+jb51
*/

$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');

user%5Bname%5D=Bob+Smith&user%5Bage%5D=47&user%5Bsex%5D=M&user%5Bdob%5D=5%2F12%2F1956
&pastimes%5B0%5D=golf&pastimes%5B1%5D=opera&pastimes%5B2%5D=poker
&pastimes%5B3%5D=rap&children%5Bbobby%5D%5Bage%5D=12&children%5Bbobby%5D%5Bsex%5D=M
&children%5Bsally%5D%5Bage%5D=8&children%5Bsally%5D%5Bsex%5D=F&0=CEO

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

class myClass {
 var $foo;
 var $baz;
 function myClass() {
 $this->foo = 'bar';
 $this->baz = 'boom';
 }
}
$data = new myClass();
echo http_build_query($data);