Characters Allowed in PHP Array Keys

PHP: special character as key in array

Change the request method to POST:

$.ajax({
    type:'POST',
    url: 'http://192.168.10.24/php/sig.php',
    data: {selectedLegalform: selection},
    ...

In PHP:

$data = $_POST['selectedLegalform'];

If you send the string GmbH & Co.KG via GET it becomes GmbH%20%26%20Co%2EKG. That should be the problem.

Unable to access array key when key name have special character

From @Jeto:

Your key probably contains HTML entities. And since you're probably dumping them on a webpage, you're not seeing them. Check the source of the page. Pretty sure you'll see Shipper's choice

associative array key changes in php for special characters

You can access these attributes directly, e.g.

echo $elem["Reference"];
echo $elem["Key"];

As @Mark Baker pointed in the right direction, the actual magic of SimpleXML happens behind the scenes. As @deceze mentionned, this is specific to SimpleXML.

You can even loop over them:

foreach($xml->foo[0]->attributes() as $a => $b) {
    echo "$a = $b \n";
}

how can add special characters to keys of array

You can use this code:

foreach ($tmp as $key=> $value) {
    unset($tmp[$key]);
    $tmp["[$key]"] = $value;
}

PHP Array Key encoding?

I tried in Japanese (as is what I can test):

$test["要"]["name"] = "要";
print_r($test);

And the result went fine, as expected.
I'm using UTF-8 for everything. I'm not sure if its a problem with your encoding settings (in php.ini) or the encoding you are using. if that is a problem, why don't you try to encode it with base64? (or other Ascii encoder). That way would be something like:

$test["6KaB"]["name"] = "要";

I'm not sure what is your goal, so let me know if it was useful.

using chinese characters as php associative array keys

To show case a very simple case of using Chinese character in associate key :-

php > $a = array("一定可以"=>TRUE);
php > var_dump($a["一定可以"]);
bool(true)
php > print_r($a);
Array
(
    [一定可以] => 1
)

Here is the example if you apply utf8_encode and utf8_decode:

php > $j = array(); $j[utf8_encode('大')] = 1; $f = array_keys($j); echo utf8_decode($f[0]);
大
php > print_r($f);
Array
(
    [0] => å¤§  /* this is garbled */
)
php > print_r($j);
Array
(
    [å¤§] => 1 /* this is garbled too */
)

One possible way to overcome:

php > print_r(utf8_decode(var_export($j, TRUE)));
array (
  '大' => 1,
)

Prepend character to key in PHP array

If you are working in PHP, then I would suggest to do any manipulation in PHP before json_encodeing.

Say your array is called $arr:

//Make array of new keys
$newKeys = array_map(function($k){return 'A'.$k;}, array_keys($arr));
//Combine new keys with value
$newArray = array_combine($newKeys, $arr);

How to remove/replace certain characters from both keys and values in an array?

No, there is no way in PHP you can modify an array key by reference. You can only add and remove keys.

Even array_change_key_case will create a new array instead of modifying the original.

You can create a new array in your function and return the new array. You can then overwrite your original array variable with the clean version.

<?php
function deleteInvalid($dirty, $ikc = [], $ivc = []) {
    $clean = [];
    foreach ($dirty as $key => $val) {
        $cKey = str_replace($ikc, '', $key);
        $cVal = str_replace($ivc, '', $val);
        $clean[$cKey] = $cVal;
    }
    return $clean;
}

$dirty = deleteInvalid($dirty);
var_dump($dirty);

You don't need to test the changes of the values after str_replace as it'll be the same if it was not changed. Unless of course your array contains more than strings... in which case you should test the type of value before modifying.

<?php
if (is_string($val)) {
    // do something with the string.
}