如何从子函数返回？

Question

我有这个功能，它负责获取 xml 中元素的特定文本。 但是每次调用该函数时，console.log 都会给我 undefined 。 我知道错误是我返回 fs.readFile 而不是 getTodayHoroscopes，但我该如何解决呢？

const getTodayHoroscope = (signNumber) => {
    fs.readFile('./horoscopy.xml', 'utf8', (err, data) => {
        if (err) {
            console.log('File read failed:', err);
        return;
        }
        try {
            parser = new DOMParser();
            xmlDoc = parser.parseFromString(data, "xml/html");
            horoscopeString = (xmlDoc.getElementsByTagName("today")[signNumber].textContent);
            result = horoscopeString
            return result;
        } catch (err) {
            console.log('Error parsing JSON:', err);
        }
    console.log(result);
    });
}

Answer 1

1. readFileSync

const getTodayHoroscope = (signNumber) => {
  try {
    const data = fs.readFileSync('./horoscopy.xml', 'utf8' )
    const parser = new DOMParser();
    const xmlDoc = parser.parseFromString(data, "xml/html");
    const horoscopeString = (xmlDoc.getElementsByTagName("today")[signNumber].textContent);
    return horoscopeString;
  } catch (error) {
    console.log(error);
  }
}

2. promise

const getTodayHoroscope =  (signNumber) => {
  return new Promise((resolve, reject) => {
    fs.readFile('./horoscopy.xml', 'utf8', (err, data) => {
      if (err) {
          console.log('File read failed:', err);
          reject(err)
          return
      }
      try {
          parser = new DOMParser();
          xmlDoc = parser.parseFromString(data, "xml/html");
          horoscopeString = (xmlDoc.getElementsByTagName("today")[signNumber].textContent);
          result = horoscopeString
          resolve(result) ;
      } catch (err) {
          console.log('Error parsing JSON:', err);
          reject(err)
      }
  });
  })
}


(async () => {
  try {
    console.log(await getTodayHoroscope('xxx'))
  } catch (error) {
    console.log(error)
  }
})();