[php] json_encode function: special characters

Elements of an array containing special characters are converted to empty strings when encoding the array with json_encode:

$arr = array ( "funds" => "ComStage STOXX®Europe 600 Techn NR ETF", "time"=>....);
$json = json_encode($arr);

After JSON encoding the element [funds] is null. It happens only with special characters (copyright, trademark etc) like the ones in "ComStage STOXX®Europe 600 Techn NR ETF".

Any suggestions?

Thanks

UPDATE: This is what solved the problem prior to populating the array (all names are taken from the db):

$mysqli->query("SET NAMES 'utf8'");

you should use this code:

$json = json_encode(array_map('utf8_encode', $arr))

array_map function converts special characters in UTF8 standard

you should add charset=UTF-8 in meta tag and use json_encode for special characters

json_encode function converts special characters in UTF8 standard

The manual for json_encode specifies this:

All string data must be UTF-8 encoded.

Thus, try array_mapping utf8_encode() to your array before you encode it:

$arr = array_map('utf8_encode', $arr);
$json = json_encode($arr);

// {"funds":"ComStage STOXX\u00c2\u00aeEurope 600 Techn NR ETF"}

For reference, take a look at the differences between the three examples on this fiddle. The first doesn't use character encoding, the second uses htmlentities and the third uses utf8_encode - they all return different results.

For consistency, you should use utf8_encode().

Docs

• json_encode()
• utf8_encode()
• array_map()

To fix the special character issue you just have to do 2 things

1.mysql_set_charset('utf8'); // set this line on top of your page in which you are using json.

2. If you are saving json data in database make sure that the particular column collation is set to "latin1_swedish_ci".

Use the below function.

function utf8_converter($array)
{
    array_walk_recursive($array, function (&$item, $key) {
        if (!mb_detect_encoding($item, 'utf-8', true)) {
                $item = utf8_encode($item);
        }
    });

    return $array;
}

To me, it works this way:

# Creating the ARRAY from Result.
$array=array();

while($row = $result->fetch_array(MYSQL_ASSOC))
{
    # Converting each column to UTF8
    $row = array_map('utf8_encode', $row);
    array_push($array,$row);
}

json_encode($array);