UTF-8

• Byte order mark — Wikipedia

• UTF-8 and Unicode Standards

• UTF-8 Everywhere

• RFC 3629 - UTF-8, a transformation format of ISO 10646

• Unicode Consortium

• Unicode Codepoint Chart and http://inamidst.com/stuff/unidata/unidata.sh

• A Programmer’s Introduction to Unicode – Nathan Reed’s coding blog

• Mechanism and Its Consequences : Validating UTF8 strings with Lookup Tables - darkcephas/utf8Validity_lookupTable: Non SIMD optimized utf8 string validator

UTF-8 est suffisamment intelligent pour coder les chars < 128 sur 1 byte et donc seulement les chars > 128 sur 2 bytes

• ANSI ( les ASCII < 128 ,plus les codepages > 128 jusqu'a 255)

• Unicode ( UTF-16/UCS-2, little endian , cad 2 bytes sont utilisés pour chaque char)

• Unicode Big Endian ( UTF-16/UCS-2, big endian, idem 2 bytes par char )

• UTF-8 ( 1 byte par char < 128, 2 bytes par char > 128)

• What Every Programmer Absolutely, Positively Needs to Know About Encodings and Character Sets to Work With Text

• UTF-8 — Wikipedia

• Unicode — Wikipedia

• Why the FAMILY emoji has a .length of 8 (2 for each emoji and 1 for each zero-width joiner) Emoji.prototype.length — a tale of characters in Unicode - Contentful

• https://github.com/mathiasbynens/utf8.js

function encodeUTF8(string) {
	var utftext = "";

	for (var n = 0; n < string.length; n++) {

		var c = string.charCodeAt(n);

		if (c < 128) {
			utftext += String.fromCharCode(c);
		}
		else if((c > 127) && (c < 2048)) {
			utftext += String.fromCharCode((c >> 6) | 192);
			utftext += String.fromCharCode((c & 63) | 128);
		}
		else {
			utftext += String.fromCharCode((c >> 12) | 224);
			utftext += String.fromCharCode(((c >> 6) & 63) | 128);
			utftext += String.fromCharCode((c & 63) | 128);
		}

	}

	return utftext;
}

Continuation bytes

Can be used to count code points (unicode chars): skip all bytes start with 10xxxxxx

// Count UTF-8 chars:
while (*c) count += ((*(c++) & 0xC0) == 0x80) ? 0 : 1;

Are part of non first bytes of multi bytes char.

• unicode - UTF-8 Continuation bytes - Stack Overflow