how to check if object is null or undefined in angular in ngIF condition

Issue

I have this inside my code:

 <div *ngIf="(listCount$| async) > 0 ">

but it won't pass the pipeline because it says

Object is possibly 'null' or 'undefined'.

in ts file:

readonly listCount$ = new BehaviorSubject<number | undefined>(undefined);

any help, can i do this in one line?

Solution

It's an async operation that might result in an undefined value that's why you are getting the error. Provide a default value in case of undefined in your template condition.

<div *ngIf="((listCount$| async) ?? 0) > 0 ">

OR set the strictNullChecks to false in your tsconfig.json file.

"strictNullChecks": false

Demo:- https://stackblitz.com/edit/angular-ivy-kheete?file=src%2Fapp%2Fapp.component.html

Answered By - Vimal Patel