title: Angular 5 FormArray
body: <p>I have this FormArray in my Angular 5 / Angular Material application: </p>
  
  <pre><code>this.form = new FormGroup({    
      customerNumberContainers: new FormArray([
        new FormGroup({
          contactTenant: new FormControl('', [Validators.required, Validators.minLength(2)]),
          customerNumber: new FormControl('', [Validators.required, Validators.minLength(2)])
          }),
      ]),
  ...
  </code></pre>
  
  <p>Actually I don't know how to run through this FormArray.
  I have tried this on</p>
  
  <pre><code>&lt;form [formGroup]="form" (ngSubmit)="onSubmit()"&gt;
      &lt;div formGroupName="customerNumberContainers"&gt;          
          &lt;div *ngFor="let customerNumberContainer of form.controls['customerNumberContainers']; index as i"&gt;
              &lt;mat-input-container class="full-width-input" style="min-width:100px;"&gt;
                   &lt;input matInput placeholder="Tenant" formControlName="customerNumberContainer[i].contactTenant"&gt;
              &lt;/mat-input-container&gt; 
              &lt;mat-input-container class="full-width-input" style="min-width:100px;"&gt;
                   &lt;input matInput placeholder="Customernumber" formControlName="customerNumberContainer[i].customerNumber"&gt;
              &lt;/mat-input-container&gt; 
          &lt;/div&gt;
      &lt;/div&gt;
     ...
  </code></pre>