if (preg_match('/^[a-zA-Z]+$/', $name)) { // Name is valid } else { // Name contains invalid characters }
$date = "05/25/2021"; if ($timestamp = strtotime($date)) { // Date is valid } else { // Date is invalid }
$email = $_POST['email']; if (!empty($email) && filter_var($email, FILTER_VALIDATE_EMAIL)) { // Email is valid } else { // Email is invalid }Package Library: No package library is required for this example as PHP has in built support for filter_var() function with FILTER_VALIDATE_EMAIL flag.