php 5.4中新增多对session状态判断的功能

1. session_start();??
2. ????
3. ??$status?=?session_status();??
4. ????
5. ??if($status?==?PHP_SESSION_DISABLED)??
6. ??{??
7. ????echo?"Session?is?Disabled";??
8. ??}??
9. ??else?if($status?==?PHP_SESSION_NONE?)??
10. ??{??
11. ????echo?"Session?Enabled?but?No?Session?values?Created";??
12. ??}??
13. ??else??
14. ??{??
15. ????echo?"Session?Enabled?and?Session?values?Created";??
16. ??}??

? 可以看到,通过使用session_status()返回的是一个int类型的值,表示出session的各种状态,比如禁止(PHP_SESSION_DISABLED ),session还不存在?
(PHP_SESSION_NONE)?
,或者session已经被建立起来了(PHP_SESSION_ACTIVE)?