angular.js - How to add an attribute to an object in angularjs, in js?

Question

For example, I write a scope like this in a jsp or html file:
<input type="text" ng-model="bb.hello"/>

Then in js, if I want to add an attribute to bb, how should I write it?

In js, if you write directly

bb.a="sdfd";
Just report the error.
So how to write something that fits this kind of thing?

Answer 1

 
$scope.bb.a = "sdfd";

Answer 2

As far as writing is concerned, if a variable in HTML, such as bb, reaches the controller, it needs to be preceded by $scope., which is $scope.bb.