title: Use of formControl inside mat-select in AngularMaterial
body: <p>The following example i have taken from Angular Material</p>
  <pre><code>&lt;mat-form-field appearance=&quot;fill&quot;&gt;
    &lt;mat-label&gt;Toppings&lt;/mat-label&gt;
    &lt;mat-select [formControl]=&quot;toppings&quot; multiple&gt;
      &lt;mat-option *ngFor=&quot;let topping of toppingList&quot; [value]=&quot;topping&quot;&gt;{{topping}}&lt;/mat-option&gt;
    &lt;/mat-select&gt;
  &lt;/mat-form-field&gt;
  
                                      
  </code></pre>
  <p>2)These is the second piece of code without formControl</p>
  <pre><code>&lt;mat-form-field appearance=&quot;fill&quot;&gt;
    &lt;mat-label&gt;Toppings&lt;/mat-label&gt;
    &lt;mat-select  multiple&gt;
      &lt;mat-option *ngFor=&quot;let topping of toppingList&quot; [value]=&quot;topping&quot;&gt;{{topping}}&lt;/mat-option&gt;
    &lt;/mat-select&gt;
  &lt;/mat-form-field&gt;
  </code></pre>
  <p><strong>ts-code</strong></p>
  <pre><code>export class SelectMultipleExample {
    toppings = new FormControl();
    toppingList: string[] = ['Extra cheese', 'Mushroom', 'Onion', 'Pepperoni', 'Sausage', 'Tomato'];
  }
  </code></pre>
  <ol start="3">
  <li><p>i don't see Any difference in the first case and second case</p>
  </li>
  <li><p>Why Even should i use mat-select with formControl ,can anyone let me  know some use cases and how  my first code is different from second</p>
  </li>
  </ol>