Angular 2 ngfor first, last, index loop
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
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
By this you can get any index in *ngFor
loop in ANGULAR ...
<ul>
<li *ngFor="let object of myArray; let i = index; let first = first ;let last = last;">
<div *ngIf="first">
// write your code...
</div>
<div *ngIf="last">
// write your code...
</div>
</li>
</ul>
We can use these alias in *ngFor
index
:number
:let i = index
to get all index of object.first
:boolean
:let first = first
to get first index of object.last
:boolean
:let last = last
to get last index of object.odd
:boolean
:let odd = odd
to get odd index of object.even
:boolean
:let even = even
to get even index of object.