title: How to initializate a mat-slide-toggle of Material Design in Angular 5?
body: <p>I can't make the initialization of a mat-slide-toggle in a Reactive Form.</p>
  
  <p>I have something like in the template</p>
  
  <pre><code>&lt;mat-slide-toggle name="X" formControlName="X" color="primary"&gt;&lt;/mat-slide-toggle&gt;
  </code></pre>
  
  <p>and in the controller I am doing </p>
  
  <pre><code>X:  new FormControl(true, [
        Validators.required
      ])
  </code></pre>
  
  <p>I have also tried with 1 or 0 or false instead of true but I didn't get it with a default value selected.</p>
  
  <p>I would appreciate if someone could help me, many thanks.</p>