In the context of PHP, what are the differences between using === null and is_null() to check for NULL values?

When checking for NULL values in PHP, using === null is a strict comparison that checks both value and type, while is_null() is a built-in function that only checks the value. Therefore, using === null is more precise and recommended when specifically checking for NULL values, as it ensures that the variable is both NULL and of the correct type.

// Using === null for strict comparison
if ($variable === null) {
    // Code to handle NULL value
}

// Using is_null() for value comparison
if (is_null($variable)) {
    // Code to handle NULL value
}