Given a form myForm with a formControl myControl you can access the control in two ways

myForm.get('myControl')

or

myForm.controls['myControl']

The second one has some advantages:

• More precise type: Accessing via controls provides a more precise type, since FormControl is a more specific interface than the generic AbstractControl returned by get.
• Less risk of errors: The IDE's autocompletion will help you avoid typing errors and will suggest the properties available for that particular control.

It would be nice if there was a rule to prefer accessing via controls instead of using the get of AbstractControl.