常见用法

json_decode ( string $json [, bool $assoc = false ]
1. $json: This function only works with UTF-8 encoded data.
2. $assoc: 当该参数为 TRUE 时,将返回 array 而非 object

string json_encode ( mixed $value)
1. $json: This function only works with UTF-8 encoded data.
intval($var);
var_dump($var);