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：
代码如下:
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:webindex.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) |
