字母索引的数组的是花括号，数字索引才是中括号

数字索引的数组示例：

$p = array('name'=>'yu','age'=>'23');

$data[0]['name']='zhangsan';

$data[0]['orderDate']='2018-02';

$data[0]['price']='58';

$data[0]['prodcut'][0]['prodcut_id']='101';

$data[0]['prodcut'][0]['prodcut_price']='28';

$data[0]['prodcut'][0]['prodcut_name']='毛巾';

$data[0]['prodcut'][1]['prodcut_id']='102';

$data[0]['prodcut'][1]['prodcut_price']='30';

$data[0]['prodcut'][1]['prodcut_name']='浴巾';

$data=json_encode($data);

echo $data;

exit;

//结果如下：

[{"name":"zhangsan","orderDate":"2018-02","price":"58","prodcut":[{"prodcut_id":"101","prodcut_price":"28","prodcut_name":"\u6bdb\u5dfe"},{"prodcut_id":"102","prodcut_price":"30","prodcut_name":"\u6d74\u5dfe"}]}]

字母索引的数组示例：

$p = array('name'=>'yu','age'=>'23');

$data=json_encode($p);

echo $data;

exit;

//结果如下：

{"name":"yu","age":"23"}