Angular’s NgForOf provides exported values that can be aliased to local variables. Until today, I’ve only been aware of the index exported value, turns out there’s a couple more.
Four of them in particular are very applicable in my day-to-day usage of Angular: first, last, even, and odd.
- first
first, a boolean value, is true when the item is the first item in the iterable.
- last
last, a boolean value, is true when the item is the last item in the iterable.
- even
even, a boolean value, is true when the item has an even index in the iterable.
- odd
odd, a boolean value, is true when the item has an odd index in the iterable.
Not leaving out index, a number representing the index of the current item in the iterable.
Here’s a usage example in which we alias the above five exported values to local variables:
<li *ngFor="let user of users; index as i; first as isFirst; last as isLast; even as isEven; odd as isOdd">
<span *ngIf="isFirst">default</span>
</li>
And that’s it 🙂, hope this is useful to you in some way.