将地理位置坐标存储到变量将在控制台中返回未定义

Question

I'm working on the weather app project on freeCodeCamp.org and am having some trouble storing the coordinates into variables. Here's what my code looks like so far.

function userLocation(){
    var lat = 0,
        lon = 0;

    if(navigator.geolocation){
      lon = navigator.geolocation.getCurrentPosition(lonPos);
      lat = navigator.geolocation.getCurrentPosition(latPos);
    }
    else{ alert("Geolocation not supported by this browser"); }

    return lat, lon;
}

function latPos(position){ return position.coords.latitude; }

function lonPos(position){ return position.coords.longitude; }

Inside the latPos() and lonPos() functions I can do console.log(position.coords.latitude) or longitude and get my coordinate. However inside the userLocation() function the lat and lon variables return undefined . What am I missing here? Here's a code pen to the project.

Answer 1

从我的脑海中，仅查看您的代码，我想您应该调用latPos和lonPos，例如：navigator.geolocation.getCurrentPosition（lonPos（））。

Answer 2

navigator.geolocation.getCurrentPosition()

takes a callback argument but it returns nothing.

So your Best bet is to use Global Variables

Something like this may work :

EDIT : There seems to be some api calls happening so you will have to do what you want from within the callback. Code below updated

function userLocation()
{
  if(navigator.geolocation)
  {
    navigator.geolocation.getCurrentPosition(Position);
  }
  else
  { 
      alert("Geolocation not supported by this browser"); 
  }
}
function Position(pos)
{
  let lat = pos.coords.latitude;
  let lon = pos.coords.longitude;

  console.log(lat,lon);
}