PHP的error_reporting错误级别变量对照表

在PHP中所有的报错信息可以用error_reporting()这个函数来设置：

它的参数有字符串和数字两种表示方法，共14个等级，但是呢，我看使用其他数字貌似也可以，起初我以为它指的是一定的报错区间，后来，终于发现了其中的规律：

error_reporting( 7 ) = error_reporting( 1+2+4)= error_reporting(E_ERROR | E_WARING | E_PARSE)

现在，我将其总结如下：

数字	常量	说明
1	E_ERROR	致命错误，脚本执行中断，就是脚本中有不可识别的东西出现 举例： Error：Invalid parameters. Invalid parameter name
2	E_WARNING	部分代码出错，但不影响整体运行 举例： Warning: require_once(E:/include/config_base.php)
4	E_PARSE	字符、变量或结束的地方写规范有误 举例：  Parse error: syntax error, unexpected $end in
8	E_NOTICE	一般通知，如变量未定义等 举例：  Notice: Undefined variable: p in E:\web\index.php on line 17
16	E_CORE_ERROR	PHP进程在启动时，发生了致命性错误 举例：  暂无
32	E_CORE_WARNING	在PHP启动时警告(非致命性错误) 举例：  暂无
64	E_COMPILE_ERROR	编译时致命性错误 举例：  暂无
128	E_COMPILE_WARNING	编译时警告级错误 举例：  暂无
256	E_USER_ERROR	用户自定义的错误消息 举例：  暂无
512	E_USER_WARNING	用户自定义的警告消息 举例：  暂无
1024	E_USER_NOTICE	用户自定义的提醒消息 举例：  暂无
2047	E_ALL	以上所有的报错信息，但不包括E_STRICT的报错信息 举例：  暂无
2048	E_STRICT	编码标准化警告，允许PHP建议如何修改代码以确保最佳的互操作性向前兼容性。

error_reporting 变量的默认值是  E_ALL & ~E_NOTICE
开发时，最佳的值为： E_ALL | E_STRICT

如果设置为：error_reporting(E_ALL | E_STRICT)，则表示记录所有的错误信息
可能会导致网站出现一大堆的错误代码；但是对于程序员来说应该说是一件好事，可以把代码优化到最优； 一些非致命性错误虽然不影响程序的运行，但是会加重PHP的负担.

最后，晒出英文版的对照表：

1	E_ERROR	Fatal run-time errors. Errors that can not be recovered from. Execution of the script is halted
2	E_WARNING	Non-fatal run-time errors. Execution of the script is not halted
4	E_PARSE	Compile-time parse errors. Parse errors should only be generated by the parser
8	E_NOTICE	Run-time notices. The script found something that might be an error, but could also happen when running a script normally
16	E_CORE_ERROR	Fatal errors at PHP startup. This is like an E_ERROR in the PHP core
32	E_CORE_WARNING	Non-fatal errors at PHP startup. This is like an E_WARNING in the PHP core
64	E_COMPILE_ERROR	Fatal compile-time errors. This is like an E_ERROR generated by the Zend Scripting Engine
128	E_COMPILE_WARNING	Non-fatal compile-time errors. This is like an E_WARNING generated by the Zend Scripting Engine
256	E_USER_ERROR	Fatal user-generated error. This is like an E_ERROR set by the programmer using the PHP function trigger_error()
512	E_USER_WARNING	Non-fatal user-generated warning. This is like an E_WARNING set by the programmer using the PHP function trigger_error()
1024	E_USER_NOTICE	User-generated notice. This is like an E_NOTICE set by the programmer using the PHP function trigger_error()
2048	E_STRICT	Run-time notices. PHP suggest changes to your code to help interoperability and compatibility of the code
4096	E_RECOVERABLE_ERROR	Catchable fatal error. This is like an E_ERROR but can be caught by a user defined handle (see also set_error_handler())
8191	E_ALL	All errors and warnings, except level E_STRICT (E_STRICT will be part of E_ALL as of PHP 6.0)