title: angular material md-select select default first value
body: <p>How to get default first option as selected when data comes from pipe?</p>
  
  <pre><code>&lt;md-select formControlName="key"&gt;
     &lt;md-option *ngFor="let elem of (elements | TesxtFilter) ; let i = index"  [value]="elem .value"&gt;
          {{ elem.name }}
     &lt;/md-option&gt;
  &lt;/md-select&gt;
  </code></pre>