Do I need to manually undo any watches in AngularJS?

Question

When a directive is instantiated, a watch is configured.

scope.$watch('propertyName', function(value) {});

Do I have do do anything to prevent a memory leak when the directive is destroyed?

Answer 1

No -- angular will take care of cleaning up watches when the associated scope gets destroyed.

If you want to clear a watch however; the $watch function returns a function, which will de-register the watch when called.

var unregister = $scope.$watch('myVar', function() { /* ... */ });
unregister();