Iterating collections in Angular templates
To iterate items in a collection in templates, use the *ngFor directive in conjunction with the *ngIf directive as below:
<ul *ngIf="errors && errors.length">
<li *ngFor="let error of errors">{{error}}</li>
</ul>The *ngIf directive is first used to determine if the dom block should be rendered at all. Next the *ngFor directive is used to iterate over the collection.