在reactjs中获取数据时获取空值

Question

我想获取我为此编写方法的一名学生的详细信息。它与邮递员一起工作但当我将它与前端连接时不工作

用于获取学生详细信息的前端控制器

export const getStudent = (studentId, token) => {
  return fetch(`${API}/student/${studentId}`, {
    method: "GET",
    headers: {
      Accept: "application/json",
      Authorization: `Bearer ${token}`,
    },
  })
    .then((response) => {
      return response.json();
    })
    .catch((err) => console.log(err));
};

设置值

const [student, setStudent] = useState({
    fullName: "",
    admissionNumber: "",
    rollNumber: "",
    age: "",
    gender: "",
    faculty: "",
    email: "",
  });

  const preload = (studentId) => {
    getStudent(user._id, token, studentId).then((student) => {
      if (student?.error) {
        setStudent(console.log(student.error));
      } else {
        setStudent(student);
      }
    });
  };

  useEffect(() => {
    preload();
  }, []);

后端

exports.getStudent = (req, res) => {
  return res.json(req.student);
};

获取状态正常，但响应为空

Answer 1

更新代码

 const preload = (studentId) => {
getStudent(studentId, token).then((data) => {
  if (data.error) {
    setStudent(console.log(data.error));
  } else {
    setStudent(student);
  }
});

};

preload只需要两个参数userid和token

在useEffect中需要传入studentId才能获取详情

 useEffect(() => {
preload(match.params.studentId);
  }, []);

在reactjs中获取数据时获取空值

Getting null while fetching data in reactjs

mongoose

node.js

express

reactjs

fetch-api