在反应中将数据从一个 state 传递到另一个 state

Question

const [object, setObject] = useState({
        id: null,
        created_date: "2021-02-18",
        classroom:"",
        name: "",
});

i want to pass the create_date value to anther state

const [notify, setNotify] = useState({
        id: 5,
        created_by: "1",
        notification:"object added",
        received_date:created_date,
});

here, i want that created_date value in received_date

Answer 1

You would have to useEffect for that since object will mutate over time, and notify has to keep up with that.

const initialObject = {
        id: null,
        created_date: "2021-02-18",
        classroom:"",
        name: "",
}

const [object, setObject] = useState(initialObject);

const [notify, setNotify] = useState({
        id: 5,
        created_by: "1",
        notification:"object added",
        received_date:initialObject.created_date,
});

useEffect(()=>{
   setNotify(notify => ({...notify, received_date: object.created_date})
}, [object])

Answer 2

Is this what you wanted to do the reference

import { useState } from "react";

export default function App() {
  const [object, setObject] = useState({
    id: null,
    created_date: "2021-02-18",
    classroom: "",
    name: ""
  });

  const [notify, setNotify] = useState({
    id: 5,
    created_by: "1",
    notification: "object added",
    received_date: object.created_date
  });

  return <div>{notify.received_date}</div>;
}