Javascript $http之外的AngularJS访问

我可以知道，为什么我不能在

$http

方法之外访问

$scope.auditorium

，但我可以在另一个

$http（$scope.auditorium）

中访问另一个

$http（$scope.auditorium）

。通过

$scope.combine在末尾连接2个作用域

代码：

      myApp.controller('displayCatController', ['$scope','$http', function($scope, $http){

              //Display auditoriums information
              $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });



              //Display exhibitions information
              $http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                    $scope.exhibitions.splice(0,1);
                        }, function errorCallback(response) {
                            console.log(response);
                        });

                    $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                    console.log($scope.combine);
      }]);

我无法访问$scope.combine，它不显示任何内容。但另一方面，如果我将$scope放在$http中，例如：

      myApp.controller('displayCatController', ['$scope','$http', function($scope, $http){

              //Display auditoriums information
              $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });


              //Display exhibitions information
              $http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                    $scope.exhibitions.splice(0,1);
                $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                console.log($scope.combine);
                        }, function errorCallback(response) {
                            console.log(response);
                        });



      }]);

如果这个问题是愚蠢的，请原谅我，我对AngularJS还是相当陌生的。谢谢你的帮助
 当您声明
$scope.combine
时，
$http
服务将异步运行，并在异步操作完成之前设置。这就是值为空的原因

解决这个问题的一个方法是等待所有异步操作完成

这里有一个例子

myApp.controller('displayCatController', ['$scope','$http','$q', function($scope, $http, $q){

              //Display auditoriums information
              var promise1 = $http({
                  method: 'GET',
                  url:'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=auditoriums&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                  }).then(function successCallback(response) {
                    $scope.auditoriums = response.data.SrchResults;
                  }, function errorCallback(response) {
                    console.log(response);
                  });


              //Display exhibitions information
              var promise2 =$http({
                        method: 'GET',
                  url: 'https://developers.onemap.sg/publicapi/themeapi/retrieveTheme?queryName=exhibitioncentres&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOjMsInVzZXJfaWQiOjMsImVtYWlsIjoicHVibGljQXBpUm9sZUBzbGEuZ292LnNnIiwiZm9yZXZlciI6ZmFsc2UsImlzcyI6Imh0dHA6XC9cL29tMi5kZmUub25lbWFwLnNnXC9hcGlcL3YyXC91c2VyXC9zZXNzaW9uIiwiaWF0IjoxNTM4Mzc5ODU3LCJleHAiOjE1Mzg4MTE4NTcsIm5iZiI6MTUzODM3OTg1NywianRpIjoiMmUxZDI2NzM0YjkxYzg2N2Y4NDdkZjI1ZTVhMzQyMjgifQ.HUmGwWO7E1MJpFADcuQyVA0h6bR2Vkkp0BQrTfrEj0k'
                        }).then(function successCallback(response) {
                            $scope.exhibitions = response.data.SrchResults;
                            $scope.exhibitions.splice(0,1);
                        }, function errorCallback(response) {
                            console.log(response);
                        });


            $q.all([promise1, promise2]).then(function(){
                $scope.combine = $scope.exhibitions.concat($scope.auditoriums, $scope.hotels);
                console.log($scope.combine);
            });

}]);

好的，谢谢！有什么办法我可以在外面找到它吗？