Convert to full unicode string

Question

How can I convert a string from \uD83D\uDE00 to full \U0001f603? json_encode() only converts to the first option...

$str = '😃';
$encode = json_encode($str);
var_dump($encode);

// string(14) ""\ud83d\ude03""

Answer 1

Assuming you have the Intl extension installed, this is easy enough to do with one of its built-in transliterators:

<?php
$str = "😀";
echo transliterator_create("Any-Hex/C")->transliterate($str);

Output:

\U0001F603