Property 'controls' does not exist on type 'AbstractControl' Angular 4 [duplicate]

Answer 1

Can use a custom interface

// Define AbstractFormGroup
export interface AbstractFormGroup extends FormGroup {
  controls: {
    [key: string]: AbstractFormGroup & AbstractFormGroup[] & AbstractControl & FormGroup & FormArray,
  }
}

// Usage example
class ... {
  myForm: AbstractFormGroup
  ...
  this.myForm = this.fb.group({...}) as AbstractFormGroup
}