How to toggle class only current element angular2

Question

here is my code examples. In my case toggle class works for every li element

   <ul class="nav nav-pills pull-right">
        <li *ngFor="let x of nav" class="presentation" (click)="active = !active" [ngClass]="toggleClass()">
            <a href="#">{{x.menu}} </a>
        </li>
    </ul>

js

 export class AppComponent {
  active = false;
  nav = NAVIGATION;

  //Toggle Class

  toggleClass(){
    if(this.active){
      return 'active';
    } else {
      return '';
    }
  }

Answer 1

With following code, you don't need to write typescript code,

<ul class="nav nav-pills pull-right">
        <li *ngFor="let x of nav;let i=index" 
             class="presentation" 
             (click)="isClicked=i"             
             [class.active]="isClicked==i">    
             <a href="#">{{x.menu}}</a>
        </li>
</ul>