use-tw-zipcode/src/index.ts

React hook for getting Taiwan zip code.

import { useState } from 'react';
import cities from './data/cities';
import districts from './data/districts';
import zipCodes from './data/zipCode';

const useTwZipCode = () => {
  const [city, setCity] = useState<string>(cities[0]);
  const [district, setDistrict] = useState<string>(districts[city][0]);
  const zipCode: string = zipCodes[city][district];

  const handleCityChange = async (value: string) => {
    await setCity(value);
    await setDistrict(districts[value][0]);
  };

  const handleDistrictChange = async (value: string) => {
    await setDistrict(value);
  };

  return {
    city,
    district,
    zipCode,
    handleCityChange,
    handleDistrictChange,
  };
};

export { cities, districts, zipCodes, useTwZipCode };