Axios函数不使用JS返回任何值

Question

I am using a function which uses axios. I want to be able to call this function and get the array I am trying to return back. Unfortunately I am getting back undefined. I don't know if I am just returning it wrong or if it has to do with axios taking time to make an api call.

Here is my code:

const filterItemsByRadius = (userRadius, items) => {
  axios
    .get('http://ip-api.com/json')
    .then(response => {
      const data = [];

      const { lat, lon } = response.data;
      items.map(item => {
        let itemGeolocation;
        if (item.geolocation) {
          itemGeolocation = item.geolocation.coords;
        }

        const currentLocation = {
          latitude: lat,
          longitude: lon,
        };
        const distanceArr = geolib.orderByDistance(currentLocation, [itemGeolocation]);
        const miles = (distanceArr[0].distance / 1609.34).toFixed(2);
        if (miles <= userRadius) {
          data.push(item);
          return data;
        }
      });
    })
    .catch(err => {
      console.log(err);
    });
};

If I call this function like so and log it out:

console.log(filterItemsByRadius(userRadius, items));

Then I will get undefined. I have logged out the data that I am returning and it is an array with the correct information so I must be doing something wrong with how I am returning it.

Answer 1

The function returns a promise. You can call it like this:

filterItemsByRadius(userRadius, items).then(resp => {
   console.log(resp);
});

You'll be able to see the result in the console now.