title: how to define index in angular material table
body: <p>how should I define an index variable when angular material table is used as ngFor is not used in this table. </p>
  
  <p>I did search for it in the documentation but index is not mentioned any where in it. </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>  &lt;mat-table #table [dataSource]="dataSource"&gt;
  
      &lt;!--- Note that these columns can be defined in any order.
            The actual rendered columns are set as a property on the row definition" --&gt;
  
      &lt;!-- Position Column --&gt;
      &lt;ng-container matColumnDef="position"&gt;
        &lt;mat-header-cell *matHeaderCellDef&gt; No. &lt;/mat-header-cell&gt;
        &lt;mat-cell *matCellDef="let element"&gt; {{element.position}} &lt;/mat-cell&gt;
      &lt;/ng-container&gt;
  
      &lt;!-- Name Column --&gt;
      &lt;ng-container matColumnDef="name"&gt;
        &lt;mat-header-cell *matHeaderCellDef&gt; Name &lt;/mat-header-cell&gt;
        &lt;mat-cell *matCellDef="let element"&gt; {{element.name}} &lt;/mat-cell&gt;
      &lt;/ng-container&gt;
  
      &lt;!-- Weight Column --&gt;
      &lt;ng-container matColumnDef="weight"&gt;
        &lt;mat-header-cell *matHeaderCellDef&gt; Weight &lt;/mat-header-cell&gt;
        &lt;mat-cell *matCellDef="let element"&gt; {{element.weight}} &lt;/mat-cell&gt;
      &lt;/ng-container&gt;
  
      &lt;!-- Symbol Column --&gt;
      &lt;ng-container matColumnDef="symbol"&gt;
        &lt;mat-header-cell *matHeaderCellDef&gt; Symbol &lt;/mat-header-cell&gt;
        &lt;mat-cell *matCellDef="let element"&gt; {{element.symbol}} &lt;/mat-cell&gt;
      &lt;/ng-container&gt;
  
      &lt;mat-header-row *matHeaderRowDef="displayedColumns"&gt;&lt;/mat-header-row&gt;
      &lt;mat-row *matRowDef="let row; columns: displayedColumns;"&gt;&lt;/mat-row&gt;
    &lt;/mat-table&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>where and how do i define an index variable for the array that  I used in this table, so that I can bind the index value in my table itself.</p>