Note: This article was written for the old *ngFor syntax, when trackBy (called track in the new @for syntax) was optional. For much of the same reasons outlined in this post, track in the a @for template is required.

In most cases, TrackByFunction is no longer needed with the new syntax, since the example mentioned in this article could simply be written in the template as:

How helping on a film set led to me down a serendipitous path, publishing a new open source library, and getting an IMDB mention.

About a year ago, a friend asked me—along with some others—to help as extra hands on set filming the second season of an absurdist comedy mini-series she was working on called Look it Up.