注意：PHP7.1中未定义的变量：grandTotal

当我对for循环中的总数求和时，我得到了一个未定义的变量。 我声明使用空字符串，但它给我非数值错误 我不知道为什么我会犯这个错误

$detail= array(
    [0] => Array
        (
            [id] => 4
            [item] => 8
            [plant] => 4
            [uom] => 1
            [t_load] => 1
            [rate] => 5
            [quantity] => 289
            [total] => 6310
        )

    [1] => Array
        (
            [id] => 5
            [item] => 13
            [plant] => 6
            [uom] => 1
            [t_load] => 1
            [rate] => 16
            [quantity] => 300
            [total] => 6310
        )
)
<?php foreach($detail as $details):?>
<tr>
    <td><?php echo $details['plant']; ?></td>
    <td><?php echo $details['item']; ?></td>
    <td><?php echo $details['t_load']; ?></td>
    <td><?php echo $details['quantity']; ?></td>
    <td><?php echo $details['rate']; ?></td>
    <td><?php echo $details['total']; ?></td>
</tr><?php

     $grandTotal += $details['total'];
endforeach; ?>

$detail=array(
[0]=>阵列
(
[id]=>4
[项目]=>8
[植物]=>4
[计量单位]=>1
[t_负载]=>1
[速率]=>5
[数量]=>289
[总计]=>6310
)
[1] =>阵列
(
[id]=>5
[项目]=>13
[植物]=>6
[计量单位]=>1
[t_负载]=>1
[速率]=>16
[数量]=>300
[总计]=>6310
)
)

在顶部定义

  <?php 
 $grandTotal  = 0;
 foreach($detail as $details):?>
<tr>
<td><?php echo $details['plant']; ?></td>
<td><?php echo $details['item']; ?></td>
<td><?php echo $details['t_load']; ?></td>
<td><?php echo $details['quantity']; ?></td>
<td><?php echo $details['rate']; ?></td>
<td><?php echo $details['total']; ?></td>
</tr><?php

    $grandTotal += $details['total'];
 endforeach; 
?>

在顶部定义

  <?php 
 $grandTotal  = 0;
 foreach($detail as $details):?>
<tr>
<td><?php echo $details['plant']; ?></td>
<td><?php echo $details['item']; ?></td>
<td><?php echo $details['t_load']; ?></td>
<td><?php echo $details['quantity']; ?></td>
<td><?php echo $details['rate']; ?></td>
<td><?php echo $details['total']; ?></td>
</tr><?php

    $grandTotal += $details['total'];
 endforeach; 
?>

---

像这样在循环之外定义

$grandTotal

<?php 
$grandTotal = 0;
foreach($detail as $details):?>
<tr>
    <td><?php echo $details['plant']; ?></td>
    <td><?php echo $details['item']; ?></td>
    <td><?php echo $details['t_load']; ?></td>
    <td><?php echo $details['quantity']; ?></td>
    <td><?php echo $details['rate']; ?></td>
    <td><?php echo $details['total']; ?></td>
</tr><?php

     $grandTotal += $details['total'];
endforeach; ?>

---

像这样在循环之外定义

$grandTotal

<?php 
$grandTotal = 0;
foreach($detail as $details):?>
<tr>
    <td><?php echo $details['plant']; ?></td>
    <td><?php echo $details['item']; ?></td>
    <td><?php echo $details['t_load']; ?></td>
    <td><?php echo $details['quantity']; ?></td>
    <td><?php echo $details['rate']; ?></td>
    <td><?php echo $details['total']; ?></td>
</tr><?php

     $grandTotal += $details['total'];
endforeach; ?>