php操作带中文的json数据

<?php
//json格式字符串转成数组
$json='{"name":"肖滔","sex":"男","age":27}';
echo $json."<br/>";
$json = iconv("gbk", "UTF-8", $json);
echo $json."<br/>";
$sr = json_decode($json, true);
if($sr)
{
   foreach($sr as $key => $value)
   {
           $sr[$key] = iconv("UTF-8", "gbk", $value);
   }   
}
echo "<pre>";
var_dump($sr);
echo "</pre>";

//编码成json格式字符串
foreach($sr as $key => $value)
{
    $sr[$key] = iconv("gbk","UTF-8",  $value);
} 
$strJson = json_encode($sr);
echo $strJson;
?>