Cannot read properties of undefined (reading 'response')-CodePudding

Getting an error while fetching data from an API the actual data I need is in response. But when I try to access it just shows up as undefined. I added a loading function but that does not seem to fix it.

Ex Json (The original is too big)

{
    "request": {
     
    },
    "response": [
      {
      Data I want here
       }

choose.js

const [data, setData] = useState();
  const [loading, setLoading] = useState(false);
  useEffect(() => {
    setLoading(true);
    fetch(
  //example API key 
      "https://airlabs.co/api/v9/flights?api_key=2a6ae284-575d-41d8-948a-b789734174dd&arr_icao=VOBL"
    )

      .then((res) => res.json())
      .then((data) => {
        setData(data);
      })
      .catch((err) => {
        console.log(err);
      })
      .finally(() => {
        setLoading(false);
      });
  }, []);

  if (loading) {
    return <div>Loading...</div>;
  }

{data.response.map((post) => {

})

Full code link - https://codesandbox.io/s/heuristic-wood-meecre?file=/choose.js:2042-2072

CodePudding user response：

You need to start with the loading state being true, because at the initial render you don't yet have data.

Also move the rendering that you do inside the map into its own component, otherwise you get a runtime error about too many hooks:

{data.response.map((post) => (
        <Inner post={post} />
      ))}

(Here the component that renders each flight data is simply named "Inner")

You can see this sandbox for full demo.