What does the '@' prefix do in PHP?

The '@' symbol in PHP is an error control operator that suppresses error messages from being displayed. When prepended to an expression, it silences any error messages that would normally be generated by that expression.

Syntax

The '@' operator is placed directly before the expression you want to suppress errors for −

@expression

Example

Here's how the '@' operator works in practice ?

<?php
// Without @ operator - shows warning
echo "Without @ operator:<br>";
$result1 = 10 / 0;
echo "Result: $result1<br><br>";

// With @ operator - suppresses warning  
echo "With @ operator:<br>";
$result2 = @(10 / 0);
echo "Result: $result2<br>";

// File operation example
echo "\nFile operations:<br>";
$content1 = file_get_contents('nonexistent.txt'); // Shows warning
$content2 = @file_get_contents('nonexistent.txt'); // Suppresses warning
echo "Operation completed<br>";
?>

Without @ operator:
Warning: Division by zero
Result: INF

With @ operator:
Result: INF

File operations:
Warning: file_get_contents(nonexistent.txt): failed to open stream: No such file or directory
Operation completed

Error Tracking

If the track_errors directive is enabled in PHP configuration, suppressed errors are stored in the $php_errormsg variable ?

<?php
// Note: track_errors is deprecated as of PHP 7.2
@($undefined_variable + 5);

if (isset($php_errormsg)) {
    echo "Error message: " . $php_errormsg;
} else {
    echo "No error tracked (track_errors disabled)";
}
?>

Best Practices

While '@' suppresses error display, it's recommended to handle errors properly instead of just hiding them. Use proper error checking mechanisms for robust code ?

<?php
// Poor practice - just hiding errors
$data = @file_get_contents('config.txt');

// Better practice - proper error handling
$data = file_get_contents('config.txt');
if ($data === false) {
    echo "Error: Could not read config file";
    // Handle the error appropriately
} else {
    echo "Config loaded successfully";
}
?>

Conclusion

The '@' operator suppresses error messages but doesn't prevent errors from occurring. Use it sparingly and always implement proper error handling for production code instead of simply hiding errors.