Example of triggering PHP errors through trigger_error in PHP, trigger_errorphp_PHP tutorial

Examples of PHP errors triggered by trigger_error in PHP, trigger_errorphp

Examples of PHP errors triggered by trigger_error in PHP

【Error suppressor @】

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

@ before any expression that would produce an error.

【Trigger PHP error through trigger_error】

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

【Example】

Copy code The code is as follows:
$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 '
The program continues to execute downwards';

Output:
Copy code The code is as follows:
3
The program continues to execute downwards

And:
Copy code The code is as follows:
$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 '
The program continues to execute downwards';

Output:
Copy code The code is as follows:
( ! ) Notice: num1 and num2 must be legal values ​​in D:practisephpErrorerror1.php on line 6

The program continues to execute downwards

【Others】When there is a serious error such as database connection failure, you can manually throw an error - use E_USER_ERROR to replace PHP's built-in E_WARNING warning.