error_reporting() 设置 PHP 的报错级别并返回当前级别。
语法error_reporting(report_level)
如果参数 level 未指定，当前报错级别将被返回。下面几项是 level 可能的值：
| 值 | 常量 | 描述 |
|---|---|---|
| 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) |
例子
任意数目的以上选项都可以用“或”来连接（用 OR 或 |），这样可以报告所有需要的各级别错误。例如，下面的代码关闭了用户自定义的错误和警告，执行了某些操作，然后恢复到原始的报错级别：
