Question

How can I convert an array of bytes into a UTF-8 string? I need this because I am extracting from a binary format.

Answer 1

A string is nothing more than an array of bytes. So a UTF-8 string is the very same as an array of bytes, except that in addition you know what the array of bytes represent.

So your input array of bytes needs one more additional information as well: the character set (character encoding). If you know the input character set, you can convert the array of bytes to another array of bytes representing an UTF-8 string.

The PHP method for doing that is called mb_convert_encoding().

PHP itself does not know of character sets (character encodings). So a string really is nothing more than an array of bytes. The application has to know how to handle that.

So if you have an array of bytes and want to turn that into a PHP string in order to convert the character set using mb_convert_encoding(), try the following:

$input = array(0x53, 0x68, 0x69);
$output = '';
for ($i = 0, $j = count($input); $i < $j; ++$i) {
    $output .= chr($input[$i]);
}
$output_utf8 = mb_convert_encoding($output, 'utf-8', 'enter input encoding here');

(Instead of the single example above, have a look at more examples at https://stackoverflow.com/a/5473057/530502.)

$output_utf8 then will be a PHP string of the input array of bytes converted to UTF-8.