How to display error level in php

How to display the error level in php: first find and open the php.ini configuration file; then set the value of the "error_reporting" item to "E_ALL", set the value of the "display_errors" item to "On"; finally save Just file.

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

Warning: Never use in production environment Show any error messages!

Display errors (display_errors) and error reporting (error_reporting) are two different things. When an error occurs in a PHP script, you can choose whether to report the error (record it in the error log) according to the settings. If display_errors is turned on in the settings, the error message will be printed to the screen at the same time.

Enable and set the display level in code

ini_set() function

For PHP , various instructions can be set through the php.ini file. But sometimes you need to set instructions when the script is running, then you need the ini_set() function.

string ini_set ( string $varname , string $newvalue )

Set the value of the specified configuration option. This option will retain its new value while the script is running, and will be restored when the script ends.

For example:

ini_set('error_reporting', E_ALL);
ini_set('display_errors', 'on');

error_reporting() function

error_reporting() The function can be run When setting the error_reporting directive. PHP has many error levels. Use this function to set the level when the script is running. If the optional argument is not set, error_reporting() returns the current error reporting level.

The default value for PHP7.2 is E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED.

It is recommended to enable E_NOTICE during the development stage to display more possible errors.

<?php

// 关闭所有PHP错误报告，相当于 ini_set(&#39;error_reporting&#39;, 0);
error_reporting(0);

error_reporting(E_ERROR | E_WARNING | E_PARSE);

// 报告 E_NOTICE  (报告未初始化的变量或捕获变量名的错误拼写)
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

// 除了 E_NOTICE，报告其他所有错误
error_reporting(E_ALL ^ E_NOTICE);

// 报告所有 PHP 错误 (参见 changelog)
error_reporting(E_ALL);

// 报告所有 PHP 错误
error_reporting(-1);

// 和 error_reporting(E_ALL); 一样
ini_set(&#39;error_reporting&#39;, E_ALL);

Modify the php.ini configuration file

error_reporting = E_ALL # 报告所有错误
display_errors = On # 显示错误

PHP predefined error constants

The official website defines all errors Constants, commonly used ones are:

• E_STRICT (integer) PHP suggestions for code modifications to ensure the best interoperability and forward compatibility of the code.
• E_ALL (integer) All error and warning information except E_STRICT.
• E_ERROR (integer) Fatal runtime error. This type of error is generally an unrecoverable situation, such as a problem caused by memory allocation. The consequence is that the script terminates and does not continue to run.
• E_WARNING (integer) Runtime warning (non-fatal error). Only a prompt message is given, but the script does not terminate.
• E_PARSE (integer) Compile-time syntax parsing error. Parsing errors are generated only by the parser.
• E_NOTICE (integer) Runtime notification. Indicates that the script encounters a situation that may appear as an error, but there may also be similar notifications in scripts that can run normally.

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