一、json_encode和json_decode区别

1、json_encode：对象/数组 ---> json

2、json_decode：json ---> 对象/数组

二、json_decode转化为数组

转化为数组时，第二个参数很重要：不加true会以PHP对象输出, 加true输出PHP数组，默认值为false

即：json_decode($str,true);

不加true时：

stdClass Object ( [data] => stdClass Object ( [access_token] => 3df2e217-fc2c-41b0-ae1f-b6da665e61ab [expires_in] => 604800 [refresh_token] => a3e7b36e-ecf7-4678-9f94-4d2bf16c4f8a [scope] => SCOPE [shop_id] => 1441968 [shop_name] => 吉祥传承饰品 ) [err_no] => 0 [message] => success )

加true时：

Array ( [data] => Array ( [access_token] => 3df2e217-fc2c-41b0-ae1f-b6da665e61ab [expires_in] => 604800 [refresh_token] => a3e7b36e-ecf7-4678-9f94-4d2bf16c4f8a [scope] => SCOPE [shop_id] => 1441968 [shop_name] => 吉祥传承饰品 ) [err_no] => 0 [message] => success )