title: Angular 7 select option selected executed twice
body: <p>I have this template</p>
  
  <pre><code>&lt;select
        [(ngModel)]="currentServer.environment"
        class="form-control form-control-sm component-form-control-color"
        id="inputGroupSelect01"&gt;
        &lt;option
          *ngFor="let environment of environments"
          [ngValue]="environment"
          [selected]="myFunction()"
          &gt;{{ environment.Name }}
        &lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>If in my controller the myFunction() contains à console.log() and if my environment array contains 4 elements, the console.log will be executed 8 times.</p>
  
  <p>Why ?</p>