JS: Char to UTF-8 Encoding 📜

Here is a function to convert character to its UTF-8 Encoding.

/*
xah_codepoint_to_utf8_hexStr(cp) return a string of hexadecimal that's the utf8 encoding of the char with codepoint cp (a integer).
The result string, space is inserted between every two hexadecimal digits (byte). Digits are in CAPITAL case.

URL http://xahlee.info/js/js_utf-8_encoding.html
Version: 2022-10-17
*/
const xah_codepoint_to_utf8_hexStr = ((
  xx,
) => ((xx <= 127)
  ? xx.toString(16).toUpperCase()
  : encodeURI(String.fromCodePoint(xx)).replace(
    RegExp("%", "g"),
    " ",
  ).trimStart()));

// s------------------------------

console.log(xah_codepoint_to_utf8_hexStr(129419));
// F0 9F A6 8B

/*
🦋
Name: BUTTERFLY
ID 129419
HEXD 1F98B
UTF8  F0 9F A6 8B
UTF16 D83E DD8B
*/

/*
to encode a string to UTF8, return array of bytes
*/
console.log((new TextEncoder()).encode("🦋"));
// Uint8Array(4) [ 240, 159, 166, 139 ]