因此，我试图构建一个脚本，计算给定邮政编码和其他邮政编码列表之间的距离，检查哪个最小。我一直在使用document.write（"）作为调试工具来检查事物的值。问题是，在变量离开回调函数的作用域后，似乎没有任何变量保留其值。例如，如果我在geocoders回调函数中为英里距离变量调用document.write，它会给我一个正确的答案。如果在将距离值存储在距离数组中的fillarray函数中调用document.write，则情况也会如此。但是，如果我在回调函数之外检查数组的值，比如在showLocations函数的末尾，那么该数组将显示为未定义。
这是我的第一个stackoverflow问题，所以我提前为回答这个问题时的任何失礼道歉。
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Google Maps JavaScript API Example: Extraction of Geocoding Data</title>
<script src="http://maps.google.com/maps?file=api&v=2&key=AIzaSyC8BdiVC-BCDF6zFhzR47dRc7gAryotnM0" type="text/javascript"></script>
<!-- According to the Google Maps API Terms of Service you are required display a Google map when using the Google Maps API. see: http://code.google.com/apis/maps/terms.html -->
<script type="text/javascript">
<cfoutput query = "getAddress">
var #toScript(zip,"zip")#;
</cfoutput>// Some coldfusion that creates the single zipcode from somewhere else
var geocoder,
function initialize() {
geocoder = new GClientGeocoder();
}
var miledistance;
var distances = new Array();
function showLocation() {
var chapters = new Array();
chapters[0] = "62650";
chapters[1] = "44323";
chapters[2] = "55555";
chapters[3] = "23624";
chapters[4] = "86753";
var closest = "10,000.0";
geocoder.getLatLng(zip,function(point){
for(var i= 0;i<5;i++){
if(point !==null){
var res= point;
geocoder.getLatLng(chapters[i],function(point){
miledistance = point.distanceFrom(res,3959);
fillarray(i, miledistance);
});
}else{
document.write("Address not Processed");
}
}
});
document.write(distance[0]);
}
function fillarray(i, distance){
distances[i] = distance;
}
function calculateDistance()
{
try
{
var glatlng1 = new GLatLng(location1.lat, location1.lon);
var glatlng2 = new GLatLng(location2.lat, location2.lon);
var miledistance = glatlng1.distanceFrom(glatlng2, 3959).toFixed(1);
var kmdistance = (miledistance * 1.609344).toFixed(1);
document.getElementById('results').innerHTML = '<strong>Address 1: </strong>' + location1.address + '<br /><strong>Address 2: </strong>' + location2.address + '<br /><strong>Distance: </strong>' + miledistance + ' miles (or ' + kmdistance + ' kilometers)';
return miledistance;
}
catch (error)
{
alert(error);
}
}
</script>
</head>
那怎么办？
http://maps.googleapis.com/maps/api/distancematrix/xml?origins=NEW-YORK-10001&destinations=WASHINGTON+20001&sensor=false
结果：
<DistanceMatrixResponse>
<status>OK</status>
<origin_address>New York, NY 10001, USA</origin_address>
<destination_address>Washington, DC 20001, USA</destination_address>
<row>
<element>
<status>OK</status>
<duration>
<value>13082</value>
<text>3 hours 38 mins</text>
</duration>
<distance>
<value>364365</value>
<text>364 km</text>
</distance>
</element>
</row>
</DistanceMatrixResponse>
来源：如何通过城市+zipCode在谷歌地图上获取距离API