title: Angular 5 'inputClick' is declared but its value is never read
body: <p>I'm new to angular and front end programming so I'm sorry if that is too easy.</p>
  
  <p>I have an <code>HTML</code> file that looks like this</p>
  
  <pre><code>&lt;input class="born-date-input" formControlName="dateOfBorn" minlength="1" maxlength="10" (click)="inputClick=true"/&gt;
  &lt;div class="alert alert-warning" *ngIf="inputClick==true"&gt;
        &lt;small&gt;show warning&lt;/small&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>In my component .ts file I have </p>
  
  <pre><code>export class MainInputFormComponent implements OnInit, DoCheck {
    @Output('changeData') sendTheNewDataJSON = new EventEmitter&lt;any&gt;();
  
    private inputClick: boolean = false;
  }
  </code></pre>
  
  <p>the <code>inputClick</code> variable is not seen in the HTML file</p>