Jquery 更新对象属性时出现问题

lon

和

lat

值应该通过调用浏览器的地理定位服务来更新。Console.log语句显示地理定位在if/else块中工作正常，但是

coords.lon

和

coords.lat

没有更新。这可能是一个范围问题吗？想法

$(document).ready(function () {
// object to hold user coordinates
    var coords = {
      lat: 0,
      lon: 0
    };

// retrieve and set user's latitude and longitude coordinates
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition( function (position) {
            coords.lon = position.coords.longitude;
            coords.lat = position.coords.latitude;
        });
    } else {
        alert("Sorry, I couldn't locate you. Here's the weather in Paris, France.");
        coords.lon = 48.8566;
        coords.lat = 2.3522;
    }

// enumerate AJAX request settings & pass in coordinate settings
    var ajaxOptions = {
        crossDomain:true,
        dataType:"json",
        url:"https://fcc-weather-api.glitch.me/api/current?",
        data: {
            lon:coords.lon,
            lat:coords.lat
        },
        method:"GET",
        success: function (json) {
            $("#description").html(JSON.stringify(json));
            alert(coords.lat);
        },
        error: function () {
            alert("Ajax request failed");
        }
    };

// make AJAX request by passing in options specified in object above
    $.ajax(ajaxOptions);

getCurrentPosition（）

是异步的。您正试图在收到数据之前使用数据发出ajax请求。当

geolocation

不可用时，在

getCurrentPosition

回调中发出ajax请求，您知道您有数据…或者在

else

中发出ajax请求

为了使读起来更清晰，将把ajax封装在一个可以从那里调用的函数中

// default coordinates - Paris
let coords = {
  lon: 48.8566,
  lat: 2.3522
}

// retrieve and set user's latitude and longitude coordinates
if (navigator.geolocation) {
  navigator.geolocation.getCurrentPosition(function(position) {
    coords.lon = position.coords.longitude;
    coords.lat = position.coords.latitude;
    // do request with user location coords
    doAjax(coords);

  });
} else {
  alert("Sorry, I couldn't locate you. Here's the weather in Paris, France.");
  // do request using default coords
  doAjax(coords);
}


function doAjax(coords) {
  // enumerate AJAX request settings & pass in coordinate settings
  var ajaxOptions = {
    crossDomain: true,
    dataType: "json",
    url: "https://fcc-weather-api.glitch.me/api/current?",
    data: {
      lon: coords.lon,
      lat: coords.lat
    },
    method: "GET",
    success: function(json) {
      $("#description").html(JSON.stringify(json));
      alert(coords.lat);
    },
    error: function() {
      alert("Ajax request failed");
    }
  };

  // make AJAX request by passing in options specified in object above
  $.ajax(ajaxOptions);
}