Example of triggering PHP errors through trigger_error in PHP_PHP tutorial

Examples of triggering PHP errors through trigger_error in PHP

This article mainly introduces examples of triggering PHP errors through trigger_error in PHP. This article introduces the error suppressor @ and triggering PHP through trigger_error. Error examples, friends in need can refer to them

Example of PHP error 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.

　@ prepended to any expression that would generate 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 and can assist in debugging the code.

【Example】

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:

The code is as follows:

　3

The program continues to execute downwards

And:

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:

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.