index.js

import { hoge, fuga, piyo } from './sample';

console.log(hoge(), fuga(), piyo()); // HOGE FUGA PIYO

import sample from './sample';

console.log(sample()); // I AM MODULE;

import * as samples from './sample';

console.log(samples); // { hoge: Function, fuga: Function, piyo: Function, default: Function }

sample.js

export const hoge = () => {
  return 'HOGE';
};

export const fuga = () => {
  return 'FUGA';
};

export const piyo = () => {
  return 'PIYO';
};

export default () => {
  return 'I AM MODULE';
};