乘以$ _POST

Question

I am trying to make a simple program where the user can multiply their inputs. But it always return a 0.

I already did:

$price = (int)$_POST['txtPrice'];

$quan = (int)$_POST['quantity'];


$ans = $quan * $price;
echo "$ans";

But returns 0 always. This is the page where all the textboxes came from:

echo "<tr>";
echo "<td><input type='text' name='quantity' placeholder='How Many?'></td>";
echo "<td><input type='text' name='txtName' value='$name'></td>";
echo "<td><input type='text' name='txtPrice' value='$price'></td>";

Answer 1

Using your same code and just adding the form tag and a submit works for me:

<?php

if(!empty($_POST)) {
    print_r($_POST);
    $price = (int)$_POST['txtPrice'];
    $quan = (int)$_POST['quantity'];

    $ans = $quan * $price;
    echo "$ans<br>";
}

echo "<tr>";
echo "<form action='index.php' method='post'>";
echo "<td><input type='text' name='quantity' placeholder='How Many?'>    </td>";
echo "<td><input type='text' name='txtName' value='$name'></td>";
echo "<td><input type='text' name='txtPrice' value='$price'></td>";
echo "<input type='submit'>";
echo "</form>";

Execute it with php -S 127.0.0.1 index.php, $ans contains the value from the multiplication.