ngfor index
/*
ngFor with index in angular is used here for generating 'li' element till the studentDetails array length.
And also make a note if you are using angular 1 then you have to replace 'let' with '#', but its ok if you are using angular 2 or above.
*/
<ul>
<li *ngFor="let student of studentDetails; index as i;" [attr.data-index]="i">
{{student}}
</li>
</ul>
/*
I hope it will help you.
Namaste
*/