Question

How do I run the PHP function htmlspecialchars() on an array of array objects?

I have the following code:

$result_set = Array
(
    [0] => Array
        (
            [home_id] => 1
            [address] => 4225 Nasmyth Dr
            [city] => Plano
            [state] => TX
            [zip] => 76798
        )

    [1] => Array
        (
            [home_id] => 8
            [address] => 4229 Nasmyth Dr
            [city] => Plano
            [state] => TX
            [zip] => 75093
        )
);

// this doesn't work since $result_set is an array of arrays and htmlspecialchars is expecting a string
htmlspecialchars($result_set, ENT_QUOTES, 'UTF-8')); 

---

UPDATE:

Please note that even though there are quite a few answers below, none of them work for an array-of-arrays. The answers below only work for simple arrays.

I’ve tried the following, but it doesn’t work:

array_walk_recursive($result_set, "htmlspecialchars", array(ENT_QUOTES,'UTF-8'))

I get the following error: htmlspecialchars() expects parameter 2 to be long, string given

---

UPDATE 2

When I try:

function cleanOutput(&$value) {
    return htmlspecialchars($value, ENT_QUOTES, 'UTF-8');
}
print_r($result_set);
print('-------');
print_r(array_walk_recursive($result_set, "cleanOutput"));

I get the following, undesired, output:

Array
(
    [0] => Array
        (
            [home_id] => 1
            [address] => 4225 Nasmyth Dr
            [city] => Plano
            [state] => TX
            [zip] => 76798
        )
    [1] => Array
        (
            [home_id] => 8
            [address] => 4229 Nasmyth Dr
            [city] => Plano
            [state] => TX
            [zip] => 75093
        )
)
-------1

---

UPDATE 3

When I try:

function cleanOutput(&$value) {
    return htmlspecialchars($value, ENT_QUOTES, 'UTF-8');
}
$result_set = Array
    (
        [0] => Array
            (
                [home_id] => 1
                [address] => 4225 Nasmyth Dr
                [city] => Plano
                [state] => TX
                [zip] => 76798
            )

        [1] => Array
            (
                [home_id] => 8
                [address] => 4229 Nasmyth Dr
                [city] => Plano
                [state] => TX
                [zip] => 75093
            )
    );

$cleanedOutput = array();
foreach ($result_set as $rs) {
    $cleaned[] = array_map("cleanOutput", $rs);
}
print_r($cleanedOutput);

I get the following, undesired, results:

{'homes' : []}

Answer 1

function filter(&$value) {
  $value = htmlspecialchars($value, ENT_QUOTES, 'UTF-8');
}
array_walk_recursive($result_set, "filter");
print_r($result_set);