Angular 2 ngfor first, last, index loop
Check out this plunkr.
When you're binding to variables, you need to use the brackets. Also, you use the hashtag when you want to get references to elements in your html, not for declaring variables inside of templates like that.
<md-button-toggle *ngFor="let indicador of indicadores; let first = first;" [value]="indicador.id" [checked]="first">
Edit: Thanks to Christopher Moore: Angular exposes the following local variables:
index
first
last
even
odd
Here is how its done in Angular 6
<li *ngFor="let user of userObservable ; first as isFirst">
<span *ngIf="isFirst">default</span>
</li>
Note the change from let first = first
to first as isFirst