The documentation:
https://docs.angularjs.org/api/ng/directive/ngRepeat
says that $index will be a key if I am iterating through an object. How do I retrieve a sequential numeric index (0,1,2...) instead? (Assuming I still wish to use an object and not an array)
Consider your object is
$scope.object = {};
$scope.object.person1 = {name: "tom", age:"5"};
$scope.object.person2 = {name: "jerry", age: "5"};
$scope.object.person3 = {name: "sparky", age: "3"};
Now you want to display the people in the object in a table.
<table>
<thead>
<th>Id</th>
<th>Name</th>
<th>Age</th>
</thead>
<tbody>
<tr ng-repeat="person in object">
<td>{{$index+1}}</td>
<td>{{person.name}}</td>
<td>{{person.age}}</td>
</tr>
</tbody>
</table>
your result would be
Id Name Age
1 tom 5
2 jerry 5
3 sparky 3
sometimes you may run into Duplicates error [ngRepeat:Dupes] using ng-repeat. The error occurs when you have duplicate entries in your array. For example
$scope.store = ["apple", "milk", "carrots", "apple"];
<li ng-repeat="item in store">{{item}}</li>
apple occurs twice, so its a duplicate. You can read more about the error at https://docs.angularjs.org/error/ngRepeat/dupes
In order to avoid the error you tell ng-repeat to use the $index to track the elements in the array by numeric indices which will always be unique.
<li ng-repeat="item in store track by $index">{{item}}</li>
you can $index in ngRepeat iteration. See below fiddle.
