The __________ function can be used in AngularJS controllers to manually initiate a digest cycle for data binding.

The $digest function can be used in AngularJS controllers to manually initiate a digest cycle for data binding. The digest cycle is the process by which AngularJS detects changes in the model and updates the view accordingly. Manually invoking $digest is useful in scenarios where automatic detection may not occur, ensuring that changes are reflected in the UI.