The PHP error reporting level controls which errors are displayed or recorded during script execution. Common types include: 1. E_ERROR fatal operation error; 2. E_WARNING non-fatal warning; 3. E_NOTICE notification information; 4. E_DEPRECATED deprecation function prompt; 5. E_PARSE syntax parsing error; 6. E_ALL all error collections. The level can be set through the php.ini configuration or the error_reporting() function. It is recommended to enable E_ALL in the development environment to find problems. The production environment should turn off the front-end display errors and only record logs. It is recommended to combine display_errors=Off, log_errors=On and specify error_log paths to ensure security and stability.

The PHP error reporting level determines which types of errors are displayed or recorded during script execution. Understanding these levels helps developers identify problems during the development and debugging phases, and also avoids exposure of sensitive information in production environments.

Common PHP error types

PHP defines multiple error levels, each representing a problem of different severity. Common ones include:

• E_ERROR : Fatal runtime error, script cannot continue execution.
• E_WARNING : Runtime warning, will not terminate the script, but may affect the result.
• E_NOTICE : Notification class information, usually a small problem such as undefined variables.
• E_DEPRECATED : indicates that the function that may be removed in the future has been used.
• E_PARSE : Compile-time syntax parsing error.
• E_ALL : A collection of all errors and warnings, usually used to enable full error reporting.

Understanding these types can help you control error output more accurately.

How to set the error reporting level?

You can set the error level by modifying the php.ini file or using the error_reporting() function in the script.

For example, enable all error prompts in the development environment:

 error_reporting(E_ALL);

And in a production environment, you may just want to log errors but not display them to the user:

 error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED);

You can also set it in conjunction with configuration file:

• display_errors = Off (production environment recommended to close)
• log_errors = On
• error_log = /path/to/your/php-error.log

This ensures that error messages are recorded without being exposed to visitors.

Common scenarios and suggestions

The recommended settings vary depending on the development stage and deployment environment:

• Development stage : Turn on E_ALL to display all errors, warnings and notifications, and detect potential problems as early as possible.
• Test environment : You can make a little restriction, such as ignoring E_DEPRECATED , but still retain most of the prompts.
• Production environment : The front-end display error ( display_errors=Off ) should be turned off, only logs should be recorded, and it is recommended to filter out non-critical information such as E_NOTICE and E_STRICT .

If you see a white screen on the page, it is very likely that E_ERROR has appeared but the display error is not enabled. At this time, you should check the error log instead of relying on the naked eye to judge.

Basically that's it. Mastering the error reporting level can greatly improve your debugging efficiency and improve the security and stability of the online environment.

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