這樣只會看到 http status 的錯誤，不能取得 response。那該怎麼取得 error response 呢？axios 文件有寫了，用 err.response: https://github.com/axios/axios#handling-errors
axios.get('/user/12345')
.catch(function (error) {
if (error.response) {
// The request was made and the server responded with a status code
// that falls out of the range of 2xx
console.log(error.response.data); // 取得內容，用 error.response.data
console.log(error.response.status); // 取得狀態碼，用 error.response.status
console.log(error.response.headers); // 取得表頭，用 error.response.headers
} else if (error.request) {
// The request was made but no response was received
// `error.request` is an instance of XMLHttpRequest in the browser and an instance of
// http.ClientRequest in node.js
console.log(error.request);
} else {
// Something happened in setting up the request that triggered an Error
console.log('Error', error.message);
}
console.log(error.config);
});