How to have angular controller respond to a variable's value change event

Question

I am building an application where I have several controllers controlling various parts of the page. I would like for them to respond to specific model change events. For example when $scope.Variable has a change of value, I would like for controller A to run a certain method etc.

How do I respond to model change events with controllers in angular?

Answer 1

@Rahil has it right: $watch method