grapheme_extract

Here's how to use grapheme_extract() to loop across a UTF-8 string character by character. <?php $str = "سabcक’…"; // if the previous line didn't come through, the string contained: //U+0633,U+0061,U+0062,U+0063,U+0915,U+2019,U+2026 $n = 0; for ( $start = 0, $next = 0, $maxbytes = strlen($str), $c = ''; $start < $maxbytes; $c = grapheme_extract($str, 1, GRAPHEME_EXTR_MAXCHARS , ($start = $next), $next) ) { if (empty($c)) continue; echo "This utf8 character is " . strlen($c) . " bytes long and its first byte is " . ord($c[0]) . "\n"; $n++; } echo "$n UTF-8 characters in a string of $maxbytes bytes!\n"; // Should print: 7 UTF8 characters in a string of 14 bytes! ?>

The other comments on this page were helpful for me. However, consider using something better than empty($value) when checking the value returned by grapheme_extract since it could as well return something like "0" (which of course evaluates to false).

Looping through grapheme clusters: <?php // Example taken from Rust documentation: https://doc.rust-lang.org/book/ch08-02-strings.html#bytes-and-scalar-values-and-grapheme-clusters-oh-my $str = "नमस्ते"; // Alternatively: //$str = pack('C*', ...[224, 164, 168, 224, 164, 174, 224, 164, 184, 224, 165, 141, 224, 164, 164, 224, 165, 135]); $next = 0; $maxbytes = strlen($str); var_dump($str); while ($next < $maxbytes) { $char = grapheme_extract($str, 1, GRAPHEME_EXTR_COUNT, $next, $next); if (empty($char)) { continue; } echo "{$char} - This utf8 character is " . strlen($char) . ' bytes long', PHP_EOL; } //string(18) "नमस्ते" //न - This utf8 character is 3 bytes long //म - This utf8 character is 3 bytes long //स् - This utf8 character is 6 bytes long //ते - This utf8 character is 6 bytes long ?>