Question

I am getting an error regarding an undefined variable. However, the calculation is correct and it displays the grand total but the error still appears within the page – here is the error:

Notice: Undefined variable: grand_total in

And here is my code:

$line_cost = $product['price'] * $item['quantity'];
  $grand_total += $line_cost;

  ?>

  <tr>
    <td><?=$product['common_name'];?></td>
    <td><input type='text' name='quantity[]' value='<?=$item['quantity'];?>' size='2' /></td>
    <td>&pound;<?=number_format($line_cost, 2);?></td>
  </tr>
  <!---
    Notice the [] on the field name for quantity - this means it is an array
    The index of the array will start at 0 (i,e. the first product) and the second will be 1, etc...
  --->
  <?php

}
?>
  <!-- Final row to put a button to recalculate -->
  <tr>
    <td colspan='3' align='center'>
      <input type='submit' name='recalc' value='Recalculate' />
    </td>
  </tr>
  <tr>
  <td>&pound;<?=number_format($grand_total, 2);?></td>
  </tr>
</table>

Answer 1

It seems $grand_total variable not defined above.

$grand_total = isset($grand_total) ? $grand_total : 0;
$line_cost = $product['price'] * $item['quantity'];
$grand_total += $line_cost;

Also you can change error reporting to not show notice/warning with error_reporting()