我如何修复未定义的索引：标题

How can i fix my undefined index: title. Why is this happining? I already tried to define index title but it did not work

Before i used href, it worked perfectly.

 <td><?= isset($restaurant_result['title']) ? $restaurant_result['title'] : '<span style="color:red">MANGLER</span>'; ?></td>

After implementing href, I am getting a undefined index: title in this statement.

<td><a href="restaurantoversigt?email=<?php echo $restaurant_result['title']?>"> <?= isset($restaurant_result['title']) ? $restaurant_result['title'] : '<span style="color:red">MISSING</span>'; ?></a></td>

You are missing isset check use the following:

<?php $title = isset($restaurant_result['title']) ? $restaurant_result['title'] : ""; ?>

<td><a href="restaurantoversigt?email=<?php echo $title ?>"> <?= $title != "" ? $title : '<span style="color:red">MISSING</span>'; ?></a></td>

try

array_key_exists('title', $restaurant_result) ? $restaurant_result['title'] : '<span style="color:red">MISSING</span>'

$restaurant_result['title'] is undefined. You weren't getting the error before because you were checking if it was undefined with isset before trying to use it.

try this :

<?php 
  $title = isset($restaurant_result['title'])?$restaurant_result['title'] :"";
?>
<?php if($title){ ?>
<td><a href="restaurantoversigt?email=<?php echo $title;?>"> <?= $title ?></a></td>
<?php } else {?>
<td><a href="restaurantoversigt?email=<?php echo $title;?>"> <span style="color:red">MISSING</span></a></td>
<?php }?>

NOTE : in else condition there will be $title null, so href will be : restaurantoversigt?email=

    <?php 
    $title = null;
    if (isset($restaurant_result['title']))
      $title = $restaurant_result['title'];
    ?>

    <td><a href="restaurantoversigt?email=<?php echo $title; ?>"> <?= $title !== null ?  $title : '<span style="color:red">MISSING</span>'; ?></a></td>

Try this:

<td><a href="restaurantoversigt?email=<?php echo $restaurant_result['title']?>"> <?php echo isset($restaurant_result['title']) ? $restaurant_result['title'] : '<span style="color:red">MISSING</span>'; ?></a></td>