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<?php $source = json_encode([new StdClass, "This is a test", "Foo's bar", 1, 5]); $escaped = implode("", array_map(function($char) { if (ctype_alnum($char)) { return $char; } $bytelen = mb_strlen($char, '8bit'); $result = '\\u'; for ($i = 0; $i < $bytelen; $i++) { $result .= str_pad(dechex(ord($char[$i])), 2, '0', STR_PAD_LEFT); } return $result; }, str_split($source, 1))); var_dump($escaped);

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