title: Angular material select - problem with displaying selected value
body: <p>Im using angular material select:
  <a href="https://material.angular.io/components/select/examples" rel="nofollow noreferrer">https://material.angular.io/components/select/examples</a></p>
  
  <p>And in my app Im using a lot of select inputs and they all have shared option array between all of them. Example array of options:</p>
  
  <pre><code>  foods: Food[] = [
  {value: 'steak-0', viewValue: 'Steak'},
  {value: 'pizza-1', viewValue: 'Pizza'},
  {value: 'tacos-2', viewValue: 'Tacos'}];
  </code></pre>
  
  <p>And my problem is: when I select any value and then I reset my option array for example with button click, then selected value dissapears from all select inputs.</p>
  
  <p><strong>Is there any way to keep the selected value visible on select input when I reset select option array or when I put explicitly new values into option array?</strong></p>
  
  <p><strong>Edited:</strong></p>
  
  <p>To be more clear, lets consider this code:</p>
  
  <p>TS file:</p>
  
  <pre><code>foods: Food[] = [
  {value: 'steak-0', viewValue: 'Steak'},
  {value: 'pizza-1', viewValue: 'Pizza'},
  {value: 'tacos-2', viewValue: 'Tacos'}];
  
  selected = 'pizza-1';
  
  resetOptions() {
      this.foods = [];
  }
  </code></pre>
  
  <p>HTML:</p>
  
  <pre><code>&lt;mat-form-field&gt;
      &lt;mat-label&gt;Favorite food&lt;/mat-label&gt;
      &lt;mat-select name="food" [(value)]="selected"&gt;
        &lt;mat-option *ngFor="let food of foods" [value]="food.value"&gt;
          {{food.viewValue}}
        &lt;/mat-option&gt;
      &lt;/mat-select&gt;
  &lt;/mat-form-field&gt;
  
  &lt;p&gt;{{selected}}&lt;/p&gt;
  
  &lt;button (click)="resetOptions()"&gt;Reset Options&lt;/button&gt;
  </code></pre>
  
  <p>And when I select value, the 'selected' propety corectly updates value and this value appears on select input, <strong>but when I click 'Reset Options' button, 'selected' propety still keeps its value, but that value disappears from select input.</strong></p>