Why does my lat /lng shows null or undefined?-CodePudding

I am trying to making IP Address Tracker using Next JS. I want the coordinates of the map to change every time the user click the button.

My Map.js file:

const Maps = ({ results }) => {
console.log(results);
const [geoData, setGeoData] = useState({ lat: null, lng: null });
let lat = results.latitude;
let lng = results.longitude;
useEffect(() => {
setGeoData({ lat: lat, lng: lng });
 }, []);
 console.log(geoData);
 return (
 <MapContainer
  center={[59.2322, -12.42221]}
  zoom={14}
  scrollWheelZoom={false}
  style={{
    height: "800px",
    width: "100%",
    position: "absolute",
    zIndex: "1",
    }}
     >
   <TileLayer
     attribution='&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
     url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
  />
  {geoData.lat && geoData.lng && (
    <Marker position={[geoData.lat, geoData.lng]} />
  )}
</MapContainer>
   );  
 };

I am passing the results from a different file.

const MapsNoSSR = dynamic(() => import("./MapsNoSSR.js"), { ssr: false 
});
 import dynamic from "next/dynamic";
  const Header () => {
   ....
  return 
<MapsNoSSR results={results} />
     }

CodePudding user response：

You would want your useEffect hook to be called again whenever results changes, so put results in its dependency array. An empty dependency array means React is going to run the effect only once

const Maps = ({ results }) => {
  const [geoData, setGeoData] = useState({ lat: null, lng: null });
  useEffect(() => {
    setGeoData({ lat: results.lattitude, lng: results.longtitude });
  }, [results]);
  return ...;
};

Also, make sure you are using the correct component. Seems like you have the Maps component then also the MapsNoSSR component