title: How to get unique id for each div?
body: <p>I am using Angular 2, and I have a <code>div</code> that I'm repeating in my markup, with a <code>click</code> event on it. The code is as shown below:</p>
  
  <p><strong>HTML:</strong></p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;button class="btn btn-primary" (click)="addExtra"&gt;
          Add Extra&lt;/button&gt;
      &lt;/div&gt;
  
      &lt;div *ngFor="let val of addExtra"&gt;
          &lt;div class="row"&gt;
              &lt;div class="col-md-2"&gt;
                  &lt;label for="title"&gt;Title&lt;/label&gt;
              &lt;/div&gt;
              &lt;div class="col-md-8"&gt;
                  &lt;input type="text" id="title" style="width:100%" class="form-control" /&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>The TypeScript code that the button is using is: </p>
  
  <pre><code>class MyClass {
      // Other things in my code...
  
      addExtra(): void {
          this.addExtra.push("inserted");
      }
  }
  </code></pre>
  
  <p>How would one add a unique id for each <code>div</code> added, so that I can have a delete button to delete that <code>div</code>?</p>