ngforin angular 8 trackby code example
Example: angular ngfor index
<ul>
<li *ngFor="let item of items; let i = index" [attr.data-index]="i">
{{item}}
</li>
</ul>
<ul>
<li *ngFor="let item of items; let i = index" [attr.data-index]="i">
{{item}}
</li>
</ul>