AngularJS :访问函数外部变量

Question

$scope.loadDistrict=function(id)
{

    $scope.districtList=[];
    angular.forEach($scope.districts,function(district, callback)
                    {
                        if(district.district_id==id)
                        {
                            $scope.districtList.push(district);
                            $scope.lat_wgs = district.lat_wgs;
                            $scope.long_wgs = district.long_wgs;
                            console.log($scope.lat_wgs);
                            console.log($scope.long_wgs);                  
                        }
                    })

};

大家好，我是第一次接触angular.My的问题，我想访问这个函数外部的变量$scope.lat_wgs和$scope.long_wgs。但是当我运行代码时，我得到了未定义的代码。

Answer 1

您需要在函数之前声明它们

$scope.lat_wgs = '';
$scope.long_wgs = '';
$scope.loadDistrict=function(id)
{
    $scope.districtList=[];
    angular.forEach($scope.districts,function(district, callback)
            {
                if(district.district_id==id)
                {
                    $scope.districtList.push(district);
                    $scope.lat_wgs = district.lat_wgs;
                    $scope.long_wgs = district.long_wgs;
                    console.log($scope.lat_wgs);
                    console.log($scope.long_wgs);                  
                }
            })
};

如果在{中括号}内声明变量，则此变量的值仅在此括号内已知。例如

foo = function(){
    var one = 1;
};
console.log(one); //oh no, i don't know what is value of 'one' variable
//well, I will output undefined

解决方案-在{方括号}前声明变量

var one = 1;
foo = function(){
    one = 2;
};
console.log(one); //it will output 2, cause value of variable 'one' changed 
//inside foo function, but it won't be undefined