Angular 2 why asterisk (*)

Question

In angular 2 document, * and template, we know that the *ngIf, *ngSwitch, *ngFor can be expanded to ng-template tag. My question is:

I think the ngIf or

Answer 1

Asterisk syntax is a syntatic sugar for more wordy template syntax which directive expands to under the hood, you are free to use any of these options.

Quote from the docs:

The asterisk is "syntactic sugar". It simplifies ngIf and ngFor for both the writer and the reader. Under the hood, Angular replaces the asterisk version with a more verbose form.

The next two ngIf examples are effectively the same and we may write in either style:

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