无法在javascript中进行乘法运算

Question

i create a page which two textbox automatically multiply show result in another textbox. But it not working.

Javascript for multiplication......

<script  type="text/javascript">
$(document).ready(function() {

    $('#dataTable').on('keyup', '.price', calTotal)
                  .on('keyup', '.quantity', calTotal);

// find the value and calculate it

    function calTotal() {
        var $row = $(this).closest('tr'),
            price    = $row.find('.price').val(),
            quantity = $row.find('.quantity').val(),
            total    = price * quantity;

// change the value in total

        $row.find('.txt').val(total)
    }

});
</script>

the html and php code is...

    <table border="1" id="dataTable">

    <tr>
    <th> Id</th>
    <th>p</th>
    <th>B</th>
    <th>M</th>
    <th>D</th>
    <th>De</th>
    <th>Q</th>
    <th>T</th>
    </tr>
    <?php
    echo"<p></p>";
    echo"<p></p>";
    echo"<p></p>";
    echo"<p><h3> Details</h3></p>";
          $order = "SELECT * FROM abd ";
          $result = mysql_query($order);

         while($row = mysql_fetch_array($result))
         {
$p= $row['p'];
  $b=$row['b'];
  $m= $row['m'];
  $dp=$row['price'];
  $q=$row['quantity'];


        echo "<td><input type=text value=$id name=item[] readonly=readonly /></td>";
        echo "<td><input type=text id=p name=p[] value=$p ></td>";
        echo "<td><input type=text id=B name=b[] value=$b ></td>";
        echo "<td><input type=text id=M name=m[] value=$m ></td>";
        echo "<td><input type=text id=Q name=qua[] value=$qua ></td>";
        echo "<td><input type=text id=price name=price[] value=$price class=price ></td>";
        echo "<td><input type=text id=Quantity name=q value=$q class=quantity ></td>";
        echo "<td><input type=text id=txt name=txt  class=txt  > </td>";
    ?>
    </table>

when i enter dprice and quantity it automatically show the value in total price. But It not working.Please Help

Answer 1

Try

total = parseInt(price) * parseInt(quantity);

This will convert your val() strings to integers to make possible math operations. If have floats use parseFloat() instead parseInt();