title: Ho to display unique values in the angular material drop down?
body: <p>I am trying to display options for the select by using angular material as shown below.</p>
  
  <p>where appitem is list of array.</p>
  
  <pre><code>&lt;mat-form-field&gt;
      &lt;mat-select placeholder="Select app" formControlName="appControl" required&gt; 
        &lt;mat-option *ngFor="let app of appitem" [value]="app.appname"&gt;
                  {{app.appname}}
        &lt;/mat-option&gt;
      &lt;/mat-select&gt;
  &lt;/mat-form-field&gt;
  </code></pre>
  
  <p>But here app.appname contains duplicate values, where I want to display only unique values.</p>
  
  <p>could you any one help on this.</p>