http_build_query函数

转自：http://blog.sina.com.cn/s/blog_5b5460eb0100grhh.html

http_build_query 

-- 生成 url-encoded 之后的请求字符串

描述

string http_build_query ( array formdata [, string numeric_prefix])

根据数组产生一个urlencode之后的请求字符串，如果在基础数组中使用了数字下标同时给出了 numeric_prefix 参数。

<?php
$data = array('foo'=>'bar',
              'baz'=>'boom',
              'cow'=>'milk',
              'php'=>'hypertext processor');
              
echo http_build_query($data);
输出：
      foo=bar&baz=boom&cow=milk&php=hypertext+processor
?> 

<?php
$data = array('foo', 'bar', 'baz', 'boom', 'cow' => 'milk', 'php' =>'hypertext processor');
              
echo http_build_query($data);
输出：
      0=foo&1=bar&2=baz&3=boom&cow=milk&php=hypertext+processor


echo http_build_query($data, 'myvar_');

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

?> 

<?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_');
 输出：（为了可读性对其进行了折行）
      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

   注意：只有基础数组中的数字下标元素“CEO”才获取了前缀，其它数字下标元素（如
   pastimes 下的元素）则不需要为了合法的变量名而加上前缀。

?>  

<?php
class myClass {
  var $foo;
  var $baz;
  
  function myClass() {
    $this->foo = 'bar';
    $this->baz = 'boom';
  }
}

$data = new myClass();

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

?>