How you encode strings like \u00d6?

Question

This is encoded: \u00d6
This is decoded: Ö

What function I have to use to decode that string into something readable?

\u00d6asdf -> Öasdf

Answer 1

To convert to UTF-8, do:

preg_replace('/\\\\u([0-9a-f]{4})/ie',
    'mb_convert_encoding("&#x$1;", "UTF-8", "HTML-ENTITIES")',
    $string);

Since this is the escaping used in JSON, another option would be json_decode. This would, however, also require escaping double quotes and backslashes before (except those of the \uXXXX escape sequences) and adding double quotes around the string. If, however, the string is indeed JSON-encoded and that's what originally motivated the question, the correct answer would naturally be use json_decode instead of the method above.