Example of a PHP error triggered by trigger_error in PHP

This article describes how to trigger a PHP error through trigger_error in PHP. This article describes the error blocker @ and the example of triggering a PHP error through trigger_error, for more information, see trigger_error in PHP.

[Error blocker @]

In addition to setting error_reporting and display_errors, error_reporting (), and ini_set () functions in php. ini, you can also use the error blocker @ to block error output.

@ Before any expression that produces an error.

[Trigger_error triggers PHP errors]

The function of triggering an error is not limited to the PHP parser, but can also be used to trigger an error through the trigger_error () function. similar to an exception thrown in an exception, an error is thrown to help debug the code.

[Example]

The code is as follows:

<? Php
$ Num1 = 1;
$ Num2 = '2 ';
If (! (Is_numeric ($ num1) & is_numeric ($ num2 ))){
// Manually throw a notification-level error
Trigger_error ('num1 and num2 must be valid number', E_USER_NOTICE );
} Else {
Echo $ num1 + $ num2;
}

Echo'
Program continues to run down ';

Output:

The code is as follows:

3
Program continues to run down

And:

The code is as follows:

<? Php
$ Num1 = 1;
$ Num2 = '2a ';
If (! (Is_numeric ($ num1) & is_numeric ($ num2 ))){
// Manually throw a notification-level error
Trigger_error ('num1 and num2 must be valid number', E_USER_NOTICE );
} Else {
Echo $ num1 + $ num2;
}

Echo'
Program continues to run down ';

Output:

The code is as follows:

(! ) Notice: num1 and num2 must be valid values in D: \ practice \ php \ Error \ error1.php on line 6

Program continues to run down

[Others] when the database cannot be connected and other serious errors, you can manually throw an error -- replace PHP's built-in E_WARNING warning with E_USER_ERROR.