@levabala/react-native-uuid/src/unparse.ts

react-native-uuid is a zero-dependency TypeScript implementation of RFC4122.

import {byteToHex} from './utils';

// **`unparse()` - Convert UUID byte array (ala parse()) into a string**

export const unparse = (buf: Array<number>, offset?: number) => {
  let i = offset || 0;
  let bth = byteToHex;

  return (
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    '-' +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]] +
    bth[buf[i++]]
  );
};