Angular2 - Add class to element with a particular id

Question

I want to add a class to element with a particular id in Angular 2.

In JavaScript, here is how it's done, but I don't have an idea on how to do it in Angular2.

document.getElementById("MyElement").className += " active";

So far, I have this:

<div id="1" [class.active]="conditionIsHere">div 1</div>
<div id="2" [class.active]="conditionIsHere">div 2</div>

Answer 1

<div id="1" [class.active]="activeId == 1" (click)="activeId=1">div 1</div>
<div id="2" [class.active]="activeId == 2" (click)="activeId=2">div 2</div>

class MyComponent {
  activeId:number;
}