how to create dynamic inputs using ng-repeat and $index - angularjs

Question

I am trying to iterate over array of questions. But I need to attach radio button answers to each question.
In this case I need to add different ng-models for each answer.
I tried the code below but it didn't work.
Is this the correct way of using $index of the ng-repeat?
<li class="fields" ng-repeat="question in questions">
<p>question:{{question.title}}</p>
<div class="radio-buttons">
<input type="radio" id="radio01" value="0" ng-model="answer[$index]" checked="checked"/>
<label for="radio01"><span></span>Yes</label>
<input type="radio" id="radio02" value="1" ng-model="answer[$index]"/>
<label for="radio02"><span></span>No</label>
</div>
</li>

Answer 1

you need to do it like this modelname{{$index}}
<li class="fields" ng-repeat="question in questions">
<p>question:{{question.title}}</p>
<div class="radio-buttons">
<input type="radio" id="radio01" value="0" ng-model="answer{{$index}}" checked="checked"/>
<label for="radio01"><span></span>Yes</label>
<input type="radio" id="radio02" value="1" ng-model="answer{{$index}}"/>
<label for="radio02"><span></span>No</label>
</div>
</li>

Answer 2

You can also do it via square bracket notation too if that pleases you aesthetically more:
<li class="fields" ng-repeat="(i, question) in questions">
<p>question:{{question.title}}</p>
<div class="radio-buttons">
<input type="radio" id="radio01" value="0" ng-model="answer[i]" checked="checked"/>
<label for="radio01"><span></span>Yes</label>
<input type="radio" id="radio02" value="1" ng-model="answer[i]"/>
<label for="radio02"><span></span>No</label>
</div>
</li>
Also to note, models are better when expressed as dot models. So for example:
<input type="radio" ng-model="answer[i]" />
Would be better as:
<input type="radio" ng-model="models.answer[i]" />
Then in your controller this makes it simple to list all the models via the object 'models', rather than finding out how many answer[i] models there are.