Trying to access array offset on value of type null (PHP)

Question

problem resolved (in comments) i am making a project for school and i am getting this error Trying to access array offset on value of type null on this line of code

<div class="user-name"><?php echo $guests["firstName"] ?></div>

it is in this code and i retrieve the information out of a database

foreach((array)$result as $guests)
        {
    ?>
    <div class="posts-container">
        <div class="post-header">
            <div class="user-details">
                <div class="user-name"><?php echo $guests["firstName"] ?></div>
                <div class="user-email"></div>
            </div>
            <div class="time"></div>
        </div>
        <div class="post-message">
            <h3></h3>
            <p></p>
        </div>
    </div>
    <?php } ?>

people asked for the sql code and the type/structure of $result type/structure: object(mysqli_result)#2 (5) { ["current_field"]=> int(0) ["field_count"]=> int(9) ["lengths"]=> NULL ["num_rows"]=> int(5) ["type"]=> int(0) sql/database:

$servername = "localhost";
$username = "root";
$password = "";
$dbname = "guestbook";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT id, firstName, lastName, email, title, message, URL, showEmail, Date FROM guestbook";
$result = $conn->query($sql);

$conn->close();

if your array is sub array then use foreach($result as $k => $guests) — Hammad Ahmed khan, Jan 21 '21 at 09:17
Please also post the array.But @HammadAhmedkhan may be right. — Alexander Dobernig, Jan 21 '21 at 09:19
Did you debug your code - often a few `var_dump()`s will help you see what's going on? Start with a `var_dump($result)` to see what data (type/structure) you actually have - share that with us. — berend, Jan 21 '21 at 09:39
Does this answer your question? ["Notice: Undefined variable", "Notice: Undefined index", and "Notice: Undefined offset" using PHP](https://stackoverflow.com/questions/4261133/notice-undefined-variable-notice-undefined-index-and-notice-undefined) — Nico Haase, Jan 26 '21 at 08:45
thanks @HammadAhmedkhan it works don't know why but it works — Olaf van Gelder, Jan 26 '21 at 09:42

score 1 · Answer 1 · answered Jan 21 '21 at 11:25

You are trying to access to a null value as an array.

In your case, $guest value is null. So, accessing to $guest['something'] will throw a "Notice: Trying to access array offset on value of type null".

Two suggestions :

Check $guest value (quick) :

foreach((array)$result as $guests)
{
    if (!is_array($guests)) {
        continue;
    }

Check $result value (better) :

If $result is a result of a SQL query, maybe try to add conditions to avoid NULL results. Or, use array_filter() before to remove empty values.

the first option worked but i the foreach doesn't give results and the second option i get a error array_filter() expects parameter 1 to be array, object given in — Olaf van Gelder, Jan 26 '21 at 08:02

azibom · Answer 2 · 2021-01-26T09:40:47.090

1

That is because this line

$result = $conn->query($sql);

That is not what you want, you need to fetch the result like this

if ($result->num_rows > 0)
while($guest = $result->fetch_assoc()) {
{?>
    <div class="posts-container">
        <div class="post-header">
            <div class="user-details">
                <div class="user-name"><?php echo $guest["firstName"] ?></div>
                <div class="user-email"></div>
            </div>
            <div class="time"></div>
        </div>
        <div class="post-message">
            <h3></h3>
            <p></p>
        </div>
    </div>
<?php } ?>

edited Jan 26 '21 at 09:40

answered Jan 26 '21 at 09:05

azibom

1,769
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the last error is gone but i now have a new error Illegal string offset 'firstName' – Olaf van Gelder Jan 26 '21 at 09:32
it fixes the error but i don't get anything from the database but it works with a other solutions but thanks – Olaf van Gelder Jan 26 '21 at 10:22
You're welcome, if my answer helped you with your question, I would appreciate it if you upvote my answer and choose it as the best answer as you wish. – azibom Jan 26 '21 at 10:36

score -1 · Answer 3 · answered Jan 26 '21 at 08:43

You can try something like this

<?php
//Array to be shown
$guests = [
        ['firstName' => 'Alex', 'email' => 'user@user.ru'] ,
        ['firstName' => 'Jhon', 'email' => 'user@user.ru']
];
?>
<div class="posts-container">
    <div class="post-header">
        <div class="user-details">
        <!-- foreach alternate syntax -->
        <?foreach ($guests as $guest):?>
            <div class="user-name"><?=$guest['firstName']?></div>
            <div class="user-email"><?=$guest['email']?></div>
        <!-- foreach alternate syntax -->
        <?endforeach;?>
    </div>
    <div class="time"></div>
</div>
<div class="post-message">
    <h3></h3>
    <p></p>
</div>

Please share more details such that others can learn from it — Nico Haase, Jan 26 '21 at 08:45

Trying to access array offset on value of type null (PHP)

3 Answers3