title: How to prevent negative/minus input values in angular 6
body: <p>Actually i have a input control with plus &amp; minus buttons, its working fine in angular 6 but now i want to prevent negative values when i decrements. How can i prevent it?</p>
  
  <p>HTML:-</p>
  
  <pre><code>&lt;span class="input-group-text cursor-pointer" (click)="travelersMinus($event)"&gt;-&lt;/span&gt;
  &lt;input type="text" class="form-control text-center" value="{{changeCount}}" /&gt;
  </code></pre>
  
  <p>TS:-</p>
  
  <pre><code>travelersMinus(evnet: Event){
          this.changeCount -= 1;
      }
  </code></pre>
  
  <p>Thanks!</p>