user_error

Function name: user_error()

Applicable version: PHP 4, PHP 5, PHP 7

Usage: The user_error() function is used to trigger a user-defined error. It allows developers to manually raise errors in the application and provides options for custom error messages and error levels.

Syntax: bool user_error ( string $error_msg [, int $error_type = E_USER_NOTICE ] )

parameter:

• error_msg: Required, defines the string that error message. Can be any valid string.
• error_type: optional, defines the integer value of the error level. The default is E_USER_NOTICE.

Return value: Return true if an error is triggered successfully; otherwise return false.

Example:

 <?php // 自定义错误处理函数function customError($error_level, $error_message, $error_file, $error_line, $error_context) { echo "自定义错误处理函数被触发："; echo "错误级别：$error_level<br>"; echo "错误消息：$error_message<br>"; echo "错误文件：$error_file<br>"; echo "错误行号：$error_line<br>"; echo "错误上下文："; print_r($error_context); } // 设置自定义错误处理函数set_error_handler("customError"); // 触发一个用户自定义错误$user_message = "这是一个自定义错误示例"; user_error($user_message, E_USER_ERROR); ?>

Output:

自定义错误处理函数被触发：错误级别：256错误消息：这是一个自定义错误示例错误文件：path/to/your/file.php错误行号：15错误上下文：Array ( )

In the example above, we first define a custom error handling function customError() , and then use set_error_handler() function to set it as the default error handling function. Next, we use user_error() function to trigger a user-defined error, specifying the error message and error level. Finally, the error handling function is called and the error details are output.

Note that user_error() function can only trigger user-defined errors at runtime and cannot handle syntax errors or other types of errors.