List bytes and codepoints in PHP

list-bytes-and-codepoints.php

<?php

/*
 * Heart emoji: ❤️
 * UTF-8 bytes: E2 9D A4 EF B8 8F
 * Code points: U+2764 U+FE0F
 */

header('Content-Type: text/plain');

$str = '❤️';

// List bytes
$bytes1 = [];
for ($i = 0, $len = strlen($str); $i < $len; $i++) {
    $bytes1[] = sprintf('%02X', ord($str[$i]));
}

echo implode(' ', $bytes1), "\n";

// List bytes (alternative 2)
$bytes2 = [];
foreach (str_split($str) as $byte) {
    $bytes2[] = sprintf('%02X', ord($byte));
}

echo implode(' ', $bytes2), "\n";

// List bytes (alternative 3)
$bytes3 = [];
preg_match_all('/./', $str, $matches);
foreach ($matches[0] as $byte) {
    $bytes3[] = sprintf('%02X', ord($byte));
}

echo implode(' ', $bytes3), "\n";

// List code points ("?" to each invalid char)
$codePoints1 = [];
for ($i = 0, $len = mb_strlen($str); $i < $len; $i++) {
    $codePoints1[] = sprintf('U+%04X', mb_ord(mb_substr($str, $i, 1)));
}

echo implode(' ', $codePoints1), "\n";

// List code points (alternative 2, "NUL" to each invalid char)
$codePoints2 = [];
foreach (mb_str_split($str) as $codePoint) {
    $codePoints2[] = sprintf('U+%04X', mb_ord($codePoint));
}

echo implode(' ', $codePoints2), "\n";

// List code points (alternative 3, ignore completely invalid string)
$codePoints3 = [];
preg_match_all('/./u', $str, $matches);
foreach ($matches[0] as $codePoint) {
    $codePoints3[] = sprintf('U+%04X', mb_ord($codePoint));
}

echo implode(' ', $codePoints3), "\n";