Reactive Forms: How to add new FormGroup or FormArray into an existing FormGroup at a later point in time in Angular 7
问题 In the other examples at StackOverflow there are many questions about using FormGroups in FormArrays. But my question is the opposite. FormArrays have a push method, that makes many things possible. FormGroups have indeed an addControl method for adding simple FormControls. Afaik FormGroups do not have addFormArray or addFormGroup method. Therefore I need your help. Following situation: this.myForm = this.fb.group({ id: this.fb.control([this.book.id]), // or short form `id: [this.book.id],` }