I am using the ionic framework to make an app. I want to do an if/else statement to display div in html . l am taking data from navigation url from page 1 to page 2 . in page 2 l use activated route params to get data from page 1 . 

Sometimes the data coming from url like that `mypage/iaw/null` so l want to check if string coming null hide div . 

what i did 

```
 public myFlag: boolean = false;
  id : any

      constructor(private nav : NavController,private activatedRoute : ActivatedRoute) {
                    this.activatedRoute.params.subscribe((params) => {

                      this.id = params['id'];
                    });

            if (this.id=="null") {
                this.myFlag = true

            }else{
              this.myFlag = false
            }

```

html 

```
  <div *ngIf="myFlag">

    <ion-button expand="block" fill="outline"color="success"  (click)="navigate(id)">Flight route</ion-button>

  </div>      
  <div *ngIf="!myFlag">

    No data 
  </div>     

```

my url example 

```
localhost/flightserachdetails/IA172/Isfahan/1555496100/CR9/scheduled/Iraqi%20Airways/IAW/null 

```