angularjs - Angular not interpolating value in array index -

i have ng-repeat in repeated value used array index value.

controller:

vm.ingredientscount = [0,1,2]; 

template

<div ng-repeat="count in vm.ingredientscount">             <h3>ingredients {{count}} {{$index}}</h3>             <formly-form model="vm.model.ingredients[$index]" fields="vm.fields.ingredients[$index]"> </formly-form>             <h4>ingredients quantity</h4>             <formly-form model="vm.model.ingredients[$index].quantity" fields="vm.fields.ingredients[$index].quantity"> </formly-form> </div> 

in rendered html {{count}} , {{index}} interpolated correctly, [$index] or [{{$index}}] not interpolate.

rendered html

<div ng-repeat="count in vm.ingredientscount">         <h3>ingredients 0 0</h3>         <formly-form model="vm.model.ingredients[$index]" fields="vm.fields.ingredients[$index]"> </formly-form>         <h4>ingredients quantity</h4>         <formly-form model="vm.model.ingredients[$index].quantity" fields="vm.fields.ingredients[$index].quantity"> </formly-form> </div>  <div ng-repeat="count in vm.ingredientscount">             <h3>ingredients 1 1</h3>             <formly-form model="vm.model.ingredients[$index]" fields="vm.fields.ingredients[$index]"> </formly-form>             <h4>ingredients quantity</h4>             <formly-form model="vm.model.ingredients[$index].quantity" fields="vm.fields.ingredients[$index].quantity"> </formly-form>     </div>  <div ng-repeat="count in vm.ingredientscount">             <h3>ingredients 2 2</h3>             <formly-form model="vm.model.ingredients[$index]" fields="vm.fields.ingredients[$index]"> </formly-form>             <h4>ingredients quantity</h4>             <formly-form model="vm.model.ingredients[$index].quantity" fields="vm.fields.ingredients[$index].quantity"> </formly-form>     </div> 

not sure formly-form doing, based on last comment of $index being spat out , [{{$index}}] not working. solution have instead:

<div ng-repeat="count in vm.ingredientscount">     <h3>ingredients {{count}} {{$index}}</h3>     <formly-form model="{{ vm.model.ingredients[$index] }}" fields="{{ vm.fields.ingredients[$index] }}"> </formly-form>     <h4>ingredients quantity</h4>     <formly-form model="{{ vm.model.ingredients[$index].quantity }}" fields="{{ vm.fields.ingredients[$index].quantity }}"> </formly-form> </div>