How to replace all emoji in string to unicode JS

Question

I have a problem with replace emoji in string to string with unicode.

For example:

I have string: const str = "My string 😀 is with emoji 😀"

I need to convert this string to const str = "My string EMOJI UNICODE is with emoji EMOJI UNICODE"

emoji unicode should look like : [e-1f60e]. Because I have function for converting string with unicode to string with emoji:

function convertEmoji(str) {
  return str.replace(/\[e-([0-9a-fA-F]+)\]/g, (match, hex) =>
    String.fromCodePoint(Number.parseInt(hex, 16))
  );
}

console.log(convertEmoji('string [e-1f60e] sadfsadfsadf'));  // "string 😎 sadfsadfsadf"

Answer 1

You can use replace as you do in your function going the other way. This answer provides a regex for modern JavaScript that matches various "emoji" ranges. Then in the callback you can use codePointAt to get the value of the code point of the emoji, convert it to hex via toString(16), and return a string in your desired format:

const str = "My string 😀 is with emoji 😀"
const rex = /[\u{1f300}-\u{1f5ff}\u{1f900}-\u{1f9ff}\u{1f600}-\u{1f64f}\u{1f680}-\u{1f6ff}\u{2600}-\u{26ff}\u{2700}-\u{27bf}\u{1f1e6}-\u{1f1ff}\u{1f191}-\u{1f251}\u{1f004}\u{1f0cf}\u{1f170}-\u{1f171}\u{1f17e}-\u{1f17f}\u{1f18e}\u{3030}\u{2b50}\u{2b55}\u{2934}-\u{2935}\u{2b05}-\u{2b07}\u{2b1b}-\u{2b1c}\u{3297}\u{3299}\u{303d}\u{00a9}\u{00ae}\u{2122}\u{23f3}\u{24c2}\u{23e9}-\u{23ef}\u{25b6}\u{23f8}-\u{23fa}]/ug;
const updated = str.replace(rex, match => `[e-${match.codePointAt(0).toString(16)}]`);
console.log(updated);

See Wiktor's answer as well. ES2018 adds Unicode property escapes. But unfortunately, support is still spotty, though the one he uses in his answer works in Chromium and its derivatives (Chrome, Brave, Chromium Edge) and iOS Safari, though sadly not yet in Firefox.

Answer 2

If you target ECMAScript 2018 and newer, you may use

/\p{Emoji}/ug

JS demo:

const str = "My string 😀 is with emoji 😀";
console.log(
  str.replace(/\p{Emoji}/ug, (m, idx) =>
   `[e-${m.codePointAt(0).toString(16)}]`
  )
);