我正在使用init如下$scope.init = function () {    $scope.getAllDetails();};$scope.getAllDetails= function () {    $http({        method: "GET",        url: "api/endpoint"    }).then(function mySuccess(response) {            $scope.processData();        }, function myError(response) {            console.log(response.statusText);        }    );};$scope.processData() = function() {//Logic to calculate var1// var1 is then passed to $scope.getID to make call to Service1.getId(var1)}我有第一個函數，它返回一個諾言：$scope.getID = function() {    return Service1.getId("abc").then(function(response){    // In above line. Instead of manually passing `abc` I want to     //pass it as variable var1      // The desired call should be as below.     //But var1 is having null here  //return Service1.getId(var1).then(function(response){        $scope.genewtId = response.data[0].Id;        console.log($scope.genewtId);        return response.data[0].Id;    }, function(error){        console.log(error.statusText);        throw error;    });};第二個函數返回一個Promise并接受一個參數：$scope.getDetails = function(id) {    var genewtID = id || $scope.genewtId;    return Service2.getDetails(genewtId).then(function(response){        $scope.data1 = response.data;        console.log($scope.data1.toString());        return response.data;    }, function(error){        console.log(error.statusText);        throw error;    });};然后鏈接兩個諾言：var promise = $scope.getId();var promise2 = promise.then(function(id) {                   return $scope.getDetails(id);               });var promise2.then(function(data) {     console.log(data);}).catch(function(error) {     console.log(error);});問題：我面對有關的問題var1中$scope.processData() 的var1總是具有null中值$scope.getID 的var1值undefined