Array in an array error

Question

I have a slice of PHP code that's throwing an error;

Notice: Array to string conversion.

It is because for some reason $deviceToken is an array when it should be a string.

I don't why PHP thinks it is an array. When I print results array of my mysqli query, it shows an array in an array, and because of that, it thinks $deviceToken is an array. I only want one array, $rows and $deviceToken to be the value variables of the array. Because of this, later in the code where $deviceToken is read in the binary, its throwing another error because apparently its an array, not a string. See below for code:

// Create an array of units assigned to call
$unitsarray = explode(",", $units);

for ($i = 0; $i < count($unitsarray); $i++){

    echo "Units row $i = $unitsarray[$i] <br />";

    $result = $mysqli->query("SELECT devicetoken FROM `department devices` WHERE unit LIKE $unitsarray[$i]");

    while($row = $result->fetch_assoc()) {
        $rows[] = $row;
    }

    echo "ResultsArray = ";
    print_r($rows);

    // Loop APNS for each device token in $devicetoken array
    foreach ($rows as $deviceToken)
    {    
    // Build the binary notification
    $msg = chr(0) . pack('n', 32) . pack("H*", $deviceToken) . pack('n', strlen($payload)) . $payload;

    // Send it to the server
    $result2 = fwrite($fp, $msg, strlen($msg));

    // Create APNS operation output
    if (!$result2)
        echo 'Failed message'.PHP_EOL;
    else
        echo "<b>Successful message sent:</b>&nbsp;&nbsp; $call - $location - $station - $units to device(s):&nbsp;&nbsp;'$deviceToken </br>".PHP_EOL;
    }
}

Results array output looks like this:

ResultsArray = Array (
    [0] => Array (
        [devicetoken] => 773f5436825a7115417d3d1e036da20e806efeef547b7c3fe4da724d97c01b30
    )
)

Psst: Mysqli has a fetch_all method, no need for while any longer: php.net/manual/en/mysqli-result.fetch-all.php - e.g. $rows = $result->fetch_all(MYSQLI_ASSOC); — hakre
– hakre, Commented Dec 16, 2012 at 23:12
Alright thanks, I have also one quick question, how do I prevent while state from throwing an error if the sql query returns no row? Right now, it goes down and returns a result, but when it reaches one where the LIKE returns nothing, it throws an error. — Jon Erickson
– Jon Erickson, Commented Dec 16, 2012 at 23:22
@JonErickson I use: $result = $db->query($query);if ($result == false){ // no rows} else {// row! } — d-_-b
– d-_-b, Commented Dec 16, 2012 at 23:27

aziz punjani · Accepted Answer · 2012-12-17 14:44:58Z

2

$deviceToken is an array, you want the key devicetoken from that array, not the array itself.

foreach ($rows as $key => $row)
{    
    $deviceToken = $row['devicetoken'];  
    // Build the binary notification
    $msg = chr(0) . pack('n', 32) . pack("H*", $deviceToken) . pack('n', strlen($payload)) . $payload;

    // Send it to the server
    $result2 = fwrite($fp, $msg, strlen($msg));

    // Create APNS operation output
    if (!$result2)
        echo 'Failed message'.PHP_EOL;
    else
        echo "<b>Successful message sent:</b>&nbsp;&nbsp; $call - $location - $station - $units to device(s):&nbsp;&nbsp;'$deviceToken </br>".PHP_EOL;
}

edited Dec 17, 2012 at 14:44

answered Dec 16, 2012 at 23:11

aziz punjani

25.8k9 gold badges49 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dharman · Accepted Answer · 2012-12-16 23:16:50Z

2

while($row = $result->fetch_assoc()) {
    $rows[] = $row;
}

$row is a 1-dimensional array
$rows is an array of arrays because each array $row is assigned as a new item in the $rows array when you print_r the array $rows it consists of other arrays

$rows as $deviceToken each value in array $rows(ie. each array $row) is taken out and assigned to $deviceToken

answered Dec 16, 2012 at 23:16

Dharman♦

33.9k27 gold badges106 silver badges157 bronze badges

Comments

codingbiz · Accepted Answer · 2012-12-16 23:12:17Z

1

$deviceToken is indeed an array, probably the first row and the only row in your resultArray

You need

$deviceToken['deviceToken']

answered Dec 16, 2012 at 23:12

codingbiz

26.4k9 gold badges62 silver badges99 bronze badges

Comments

kadeempardue · Accepted Answer · 2012-12-16 23:13:14Z

1

It is an array because your using fetch_assoc, the results return an array (keys are the database column names, the values are the values of the fields). It returns the keys and values from the database and stores it in an array object. fetch_rows returns just the rows. Look into using a different query function method. Also I agree with the other two. You'll have to separate the rows as $key => $value.

answered Dec 16, 2012 at 23:13

kadeempardue

895 bronze badges

Comments

staticsan · Accepted Answer · 2012-12-16 23:13:55Z

0

You're creating an array of arrays when you loop over the resultset returned by ->fetch_assoc(). This is apparant in the print_r(). It is because ->fetch_assoc() returns an array of the data, even if there's one column.

answered Dec 16, 2012 at 23:13

staticsan

30.6k5 gold badges64 silver badges72 bronze badges

Collectives™ on Stack Overflow

Array in an array error

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related