PHP multiple variables in a form

Here is a basic example. Submitting the form does not reset the fields.

You can either store all values in separate variables such as $guest1, $guest2, etc, but an array is much easier to use when handling the $_POST data.

Before touching any of the variables we check if the variable is set with isset to prevent errors.

<?php

// Set up the number of guests
if(isset($_POST['guestnumber'])) {
    $numGuests = (int)$_POST['guestnumber'];
    if ($numGuests < 1) {
        $numGuests = 1;
    }
}

if (isset($_POST['guests'])) {
    // Handle guest data
}

?>

<form method="POST" action="">
    <input type="text" name="guestnumber" size="6" value="<?php

        // Retain field value between refreshes
        if(isset($numGuests)) echo $numGuests; ?>"><br>

    <?php

    // Echo out required number of fields
    if (isset($numGuests)) {
        for ($i = 0; $i < $numGuests; $i++) {

            // Store field information in a 'guests' array
            echo "<input type='text' name='guests[]' value='";

            // Retain the guest names between refreshes
            if (isset($_POST['guests'])) {
                echo $_POST['guests'][$i];
            }

            echo "'><br>";
        }
    }

    ?>
    <input type="submit" value="Submit">
</form>