; Error Level Constants:
; E_ALL - All errors and warnings (includes E_STRICT as of PHP 5.4.0)
; E_ALL 所有错误和警告（除E_STRICT外）
; E_ERROR - fatal run-time errors
; E_ERROR 致命的错误。脚本的执行被暂停。
; E_RECOVERABLE_ERROR - almost fatal run-time errors
; E_RECOVERABLE_ERROR 大多数的致命错误。
; E_WARNING - run-time warnings (non-fatal errors)
; E_WARNING 非致命的运行时错误，只是警告，脚本的执行不会停止。
; E_PARSE - compile-time parse errors
; E_PARSE 编译时解析错误，解析错误应该只由分析器生成。
; E_NOTICE - run-time notices (these are warnings which often result from a bug in your code, but it's possible that it was intentional (e.g., using an uninitialized variable and relying on the fact it's automatically initialized to an empty string)
; E_NOTICE 脚本运行时产生的提醒（往往是我们写的脚本里面的一些bug，比如某个变量没有定义），这个错误不 会导致任务中断。
; E_STRICT - run-time notices, enable to have PHP suggest changes to your code which will ensure the best interoperability and forward compatibility of your code
; E_STRICT 脚本运行时产生的提醒信息，会包含一些php抛出的让我们要如何修改的建议信息。
; E_CORE_ERROR - fatal errors that occur during PHP's initial startup
; E_CORE_ERROR 在php启动后发生的致命性错误
; E_CORE_WARNING - warnings (non-fatal errors) that occur during PHP's nitial startup
; E_CORE_WARNING 在php启动后发生的非致命性错误，也就是警告信息
; E_COMPILE_ERROR - fatal compile-time errors
; E_COMPILE_ERROR php编译时产生的致命性错误
; E_COMPILE_WARNING - compile-time warnings (non-fatal errors)
; E_COMPILE_WARNING php编译时产生的警告信息
; E_USER_ERROR - user-generated error message
; E_USER_ERROR 用户生成的错误
; E_USER_WARNING - user-generated warning message
; E_USER_WARNING 用户生成的警告
; E_USER_NOTICE - user-generated notice message
; E_USER_NOTICE 用户生成的提醒
; E_DEPRECATED - warn about code that will not work in future versions of PHP
; E_USER_DEPRECATED - user-generated deprecation warnings
& 表示并且
~ 表示非
| 表示或者
比如： error_reporting = E_ALL & ~E_NOTICE 表示错误级别为E_ALL 并且除了E_NOTICE