Sorting Array by key

ionic-v1
1

Hi,

how i can sort this array by the index/key?
This is my Code

<ion-content class="has-header">
        <div class="row">
            <div class="col">
                <ion-list>
                    <div class="accGroup" ng-repeat="productList in productLists">
                        <ion-item class="item-stable" ng-click="toggleGroup(productList)" ng-class="{active: isGroupShown(productList)}">
                            <i class="icon" ng-class="isGroupShown(productList) ? 'ion-minus' : 'ion-plus'"></i>&nbsp; {{productList.name}}
                        </ion-item>
                        <ion-item class="item-accordion" ng-repeat="item in productList.items" ng-show="isGroupShown(productList)" href="#/app/{{item.path}}">{{item.name}}</ion-item>
                    </div>
                </ion-list>
            </div>
        </div>
    </ion-content>

This my Array

$scope.productLists = [{
  name: 'lorem',
  shown: false,
  items: {
    0: {
      name: 'lorem'
    },
    1: {
      name: 'lorem'
    },
    2: {
      name: 'lorem'
    },
    3: {
      name: 'lorem'
    },
    [...]
    9: {
      name: 'lorem'
    },
    10: {
      name: 'lorem'
    },
    11: {
      name: 'lorem'
    },
    12: {
      name: 'lorem'
    }
  }
}];

The Output is that … i want a sort by the Index/key

0
1
10
11
12
2
3
4
…

Thanks for help