title: Angular2: Set placeholder for select
body: <p>I have a select dropdown like this</p>
  
  <pre><code>&lt;select class="form-control" id="sel1" [(ngModel)]="studentObj.department" name="dept"&gt;
  
    &lt;option *ngFor="let dept of departmentList" [ngValue]="dept"&gt;{{dept}}&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>While adding a student it should show the placeholder as "Select Dept" and while editing student it should show the selected value.
  I tried adding </p>
  
  <pre><code>&lt;option value="" disabled="true" [selected]="true"&gt;--please select--&lt;/option&gt;
  </code></pre>
  
  <p>But its not getting selected by default.</p>