What are the implications of using preg_match in PHP functions and how should its return values be handled for accurate evaluation?

When using preg_match in PHP functions, it is important to handle its return values properly for accurate evaluation. The preg_match function returns 1 if the pattern is found in the subject string, 0 if no matches are found, and false if an error occurs. To accurately evaluate the result, you should use strict comparison operators (===) to check for a match.

// Example code snippet to handle preg_match return values
$subject = "Hello World";
$pattern = "/hello/i"; // case-insensitive pattern

if (preg_match($pattern, $subject) === 1) {
    echo "Pattern found in the subject string.";
} elseif (preg_match($pattern, $subject) === 0) {
    echo "Pattern not found in the subject string.";
} else {
    echo "An error occurred while evaluating the pattern.";
}