Example of trigger_error triggering PHP error in PHP

【Error suppression character @】

In addition to the error_reporting and display_errors settings, error_reporting() function, and ini_set() function in , you can also use the error suppressor @ to block the output of the error.

@ Add before any expression that will produce an error.

【Trigger PHP errors with trigger_error】

The function of triggering errors is not limited to PHP parser, but can also trigger errors through trigger_error() function. Similar to the exception thrown in an exception, an error can be thrown to assist in debugging the code.

【example】

Copy the codeThe code is as follows:

<?php
$num1 = 1;
$num2 = '2';
if(!(is_numeric($num1) && is_numeric($num2))){
//Manually throw notification level errors
trigger_error('num1 and num2 must be legal values', E_USER_NOTICE);
}else{
echo $num1 + $num2;
}

echo '<br />The program continues to execute downward';

Output:

Copy the codeThe code is as follows:

3
The program continues to be executed downward

and:

Copy the codeThe code is as follows:

<?php
$num1 = 1;
$num2 = '2a';
if(!(is_numeric($num1) && is_numeric($num2))){
//Manually throw notification level errors
trigger_error('num1 and num2 must be legal values', E_USER_NOTICE);
}else{
echo $num1 + $num2;
}

echo '<br />The program continues to execute downward';

Output:

Copy the codeThe code is as follows:

( ! ) Notice: num1 and num2 must be legal values ​​in D:\practise\php\Error\ on line 6

The program continues to be executed downward

【Others】When a serious error is not connected to the database, you can manually throw an error - replace the built-in E_WARNING warning in PHP with E_USER_ERROR.