<form action="action.php" method="post">
  <p>Your name: <input type="text" name="name"/></p>
  <p>Your age: <input type="text" name="age" /></p>
  <p><input type="submit" /></p>
</form>
Hi <?php echo htmlspecialchars($_POST['name']); ?>.
You are <?php echo (int)$_POST['age']; ?> years old.
<form action="action.php" method="post">
  <p>Your Email: <input type="text" name="email"/></p>
  <p><input type="submit" /></p>
</form>
<?php
$email = $_POST['email'];
$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/';
if (preg_match($regex, $email)) {
 echo $email . " is valid";
} else {
 echo $email . " is invalid.";
}
?>
 <br>
 <br>


<?php
$phone_numbers = array(
    '555-555-5555',
    '555 555 5555',
    '1(519) 555-4444',
    '1 (519) 555-4422',
    '1-555-555-5555',
    '1-(555)-555-25555',
);
$regex = "/^(\d[\s-]?)?[\(\[\s-]{0,2}?\d{3}[\)\]\s-]{0,2}?\d{3}[\s-]?\d{4}$/i";
foreach( $phone_numbers as $number ) {
    echo $number . ': ' . ( preg_match( $regex, $number ) ? 'valid' : 'invalid' ) . '<br/>';
}
?>