PHP custom error handling function trigger_error of

Define and use the trigger_error() function to create user-defined error messages.
trigger_error() is used to trigger an error message under a user-specified condition. It works with the built-in fault handler 1 and can also be used with user-defined functions created by the set_error_handler() function.

If an illegal error type is specified, the function returns false, otherwise true.
Grammar trigger_error (error_message error_types)
The parameter description error_message is required. Specify error messages. The length limit is 1024 characters. error_types optional. Specifies the error type of the error message. Possible values: • E_USER_ERROR
•E_USER_WARNING
•E_USER_NOTICE

 
<?php 
function myError($errno,$errstr,$errfile,$errline){ 
switch($errno){ 
case E_USER_ERROR: 
echo "<b>My ERROR</b>[$errno] $errstr<br />"; 
echo "Fatal error in line $errline of file $errfile"; 
exit(1); 
break; 
case E_USER_WARNING: 
echo "<b>My WARNING</b> [$errno] $errstr"; 
break; 
default: 
echo "Unknown error type:[$errno] $errstr"; 
break; 
} 
} 
set_error_handler("myError"); 
$age=-100; 
if($age<0){ 
trigger_error('age you input must>=0',E_USER_ERROR); 
} 
?>