无法读取未定义的属性'results' - var lat = data.results[0].geometry.location.lat;

Question

添加位置并按回车键时出错

var lat = data.results[0].geometry.location.lat;

TypeError: Cannot read property 'results' of undefined

有时它会给出无法读取未定义错误的"几何"

//CREATE - add new campground to DB
router.post("/", isLoggedIn, isSafe, function(req, res){
// get data from form and add to campgrounds array
var name = req.body.name;
var image = req.body.image;
var desc = req.body.description;
var author = {
id: req.user._id,
username: req.user.username
}
var cost = req.body.cost;
geocoder.geocode(req.body.location, function (err, data) {
var lat = data.results[0].geometry.location.lat;
var lng = data.results[0].geometry.location.lng;
var location = data.results[0].formatted_address;
var newCampground = {name: name, image: image, description: desc, cost: cost, author:author, location: location, lat: lat, lng: lng};
// Create a new campground and save to DB
Campground.create(newCampground, function(err, newlyCreated){
if(err){
console.log(err);
} else {
//redirect back to campgrounds page
console.log(newlyCreated);
res.redirect("/campgrounds");
}
});
});
});

var lat = data.results[0].geometry.location.lat;
^
TypeError: Cannot read property 'results' of undefined
at /home/shuaib/Desktop/The Web Developement Bootcamp/avasco/routes/campgrounds.js:54:20
at Request._callback (/home/shuaib/Desktop/The Web Developement Bootcamp/avasco/node_modules/geocoder/providers/google.js:17:7)
at Request.self.callback (/home/shuaib/Desktop/The Web Developement Bootcamp/avasco/node_modules/geocoder/node_modules/request/request.js:185:22)
at emitTwo (events.js:126:13)
at Request.emit (events.js:214:7)
at Request.<anonymous> (/home/shuaib/Desktop/The Web Developement Bootcamp/avasco/node_modules/geocoder/node_modules/request/request.js:1161:10)
at emitOne (events.js:116:13)
at Request.emit (events.js:211:7)
at IncomingMessage.<anonymous> (/home/shuaib/Desktop/The Web Developement Bootcamp/avasco/node_modules/geocoder/node_modules/request/request.js:1083:12)
at Object.onceWrapper (events.js:313:30)
at emitNone (events.js:111:20)
at IncomingMessage.emit (events.js:208:7)
at endReadableNT (_stream_readable.js:1064:12)
at _combinedTickCallback (internal/process/next_tick.js:138:11)
at process._tickCallback (internal/process/next_tick.js:180:9)

Answer 1

来自Google API：

地理编码(请求、回调(

参数：

请求：地理编码器请求

回调：函数(数组，地理编码器状态(

返回值：无

对请求进行地理编码。

意思 - 您在代码中颠倒了"结果"和"错误"(实际上是状态(的顺序。

这应该是：

geocoder.geocode(req.body.location, function (**data, err**) { /*geocoder callback */ }

Answer 2

控制台你的err对象。然后你可以找到应该出错的地方。 结果是undefined，因为data是null或undefined。 试试这个。

var geocoder = new google.maps.Geocoder();
var address = "new york";
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var latitude = results[0].geometry.location.lat();
var longitude = results[0].geometry.location.lng();
console.log(latitude,longitude);
} 
}); 

Answer 3

数据现在被重新格式化：var 语法为：

var lat = data[0].latitude;
var lng = data[0].longitude;
var location = data[0].formattedAddress;

查看从 api 返回的内容的简单方法是 控制台.log(数据(