What is a FormArray?

import { Component } from '@angular/core';
import { FormArray, FormControl, FormGroup, ReactiveFormsModule } from '@angular/forms';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [ReactiveFormsModule],
  template: `
    <form [formGroup]="form">
      <div formArrayName="phones">
        <input *ngFor="let c of phones.controls; let i = index" [formControlName]="i" />
      </div>
      <button (click)="add()">Add phone</button>
    </form>
  `,
})
export class AppComponent {
  form = new FormGroup({ phones: new FormArray([new FormControl('')]) });
  get phones() { return this.form.get('phones') as FormArray; }
  add() { this.phones.push(new FormControl('')); }   // dynamic
}