selected option in ng-options in agularjs - angularjs

Question

I would like to have a selected option in the dynamic select box.
select box not showing any value as selected
$http({
method: 'GET',
url: $rootScope.API_URL + 'branchesShow/' + $routeParams.id,
}).then(function successCallback(response) {
$scope.city_id = response.data.data.city_id;
}, function errorCallback(response) {
// console.log(response);
});
$http({
method: 'GET',
url: $rootScope.API_URL + 'citySelectList',
}).then(function successCallback(response) {
$scope.cities = response.data.data;
console.log($scope.cities);
}, function errorCallback(response) {
console.log(response);
});
<select class = "form-control" ng-model="city_id" ng-options="c.id as c.title for c in cities">
</select>

Answer 1

I think your $scope.city_id doesn't contain an appropriate id value, as i can see you have ng-model directive and an option should be selected if the value in city_id matches an id of an object in your list.
Check if there is something wrong in the data, here is a little snippet to help you :
angular.module('myApp', [])
.controller('MyCtrl', function ($scope) {
$scope.cities = [
{
id: 1,
title: 'City 1'
},
{
id: 2,
title: 'City 2'
},
]
$scope.city_id = 1;
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>
<div ng-app="myApp" ng-controller="MyCtrl">
<select class = "form-control" ng-model="city_id" ng-options="c.id as c.title for c in cities">
</select>
</div>