Q:

Unicode characters from JSON.stringify to real unicode characters

I use JSON.stringify() function to stringify JS objects for AJAX sending to PHP.
The problem arises when JSON.stringify function encodes unicode characters to format \uxxxx (eg. \u000a). My question is how to convert those characters to regular unicode characters in PHP?

A:

See Output UTF-16? A little stuck
This converts to UTF-8:
function unescape_utf16($string) {
    /* go for possible surrogate pairs first */
    $string = preg_replace_callback(
        '/\\\\u(D[89ab][0-9a-f]{2})\\\\u(D[c-f][0-9a-f]{2})/i',
        function ($matches) {
            $d = pack("H*", $matches[1].$matches[2]);
            return mb_convert_encoding($d, "UTF-8", "UTF-16BE");
        }, $string);
    /* now the rest */
    $string = preg_replace_callback('/\\\\u([0-9a-f]{4})/i',
        function ($matches) {
            $d = pack("H*", $matches[1]);
            return mb_convert_encoding($d, "UTF-8", "UTF-16BE");
        }, $string);
    return $string;
}

