无法获取谷歌地图computeDistanceBetween()以返回值

Question

computeDistanceBetween()谷歌地图几何库中的功能不会为我返回值.使用该alert函数,它表示距离为"[object,Object]".谁能看到我哪里出错了？以下是相关代码的重要部分:

<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false&libraries=geometry"></script>
<script type="text/javascript" >

    var myArray1= [['location1', lat1, lng1], ['location2', lat2, lng2], ...];
    var myArray2= [['locationA', latA, lngA], ['locationB', latB, lngB], ...];
    var arrays = [myArray1, myArray2];

    function codeStart() {
      var orig;
      var startAddress = document.getElementById("start").value;
      geocoder.geocode( { 'address': startAddress}, function(results, status) {
            if (status == google.maps.GeocoderStatus.OK) {
                var i = 0;
                var input = results[0].geometry.location;
                while (i < arrays.length) {             
                    orig = closest(input, arrays[i]);
                }
            }
      });
    }

    function closest(latlng, array){
      var distance;
      var c = 0;
      while (c < array.length){
          var location = array[c];
          var locationlatlng = new google.maps.LatLng(location[1],location[2]);
          distance = new google.maps.geometry.spherical.computeDistanceBetween(latlng, locationlatlng);
          alert(distance);  // popup box says "[object, Object]"
          c++;
      }
    }

</script>

Answer 1

computeDistanceBetween是一种静态方法.所以这一行:

distance = new google.maps.geometry.spherical.computeDistanceBetween(latlng, locationlatlng);

应该是这样:

distance = google.maps.geometry.spherical.computeDistanceBetween(latlng, locationlatlng)

顺便alert()说一下,当告诉你某个东西是一个对象时,现在是切换到的好时机,console.dir()而不是alert()这样你可以(至少在某些浏览器中)查看console/dev工具中对象的内容.如果您对JavaScript控制台了解不多,请查看它.它将为您节省大量时间.