对 axios 检索的数据的无效挂钩调用

Question

I'm trying to retrieve the JSON data from here and then update the state in a functional component. Even though the code seems fine I'm getting an error saying its an invalid hook call.

On the react documentation it said that I might have 2 different react apps in the same folder however I checked it with the command they gave and there was only 1. However I am running this from a django server and there is a different react app in a different django app (so in a completely different folder).

const App = () => {
  const [posts, setPosts] = useState([]);

  useEffect(() => {
    let url = "https://jsonplaceholder.typicode.com/posts";
    axios.get(url).then(res => {
      console.log(res.data);
      // The code crashes here saying that it is an invalid hook call
      useState(res.data);
    }).catch(err => console.log(err));
  }, []);

  return (
    <div>
      This is just a place holder.
    </div>
  );
}

I have a feeling this might have something to do with the other react application in the django project but if anyone can see something that I can't I would appreciate the help.

Edit I realised that I was trying to call useState() in the useEffect hook when I should have been using the setPosts function that was already defined in the function.

Answer 1

 // The code crashes here saying that it is an invalid hook call

It crashes there because you are not using the state hook correctly. You should call setPosts instead of useState . See docs .