how to hide a button in angular code example

Example 1: hide button in typescript

var link = document.getElementById('nav-ask');
link.style.display = 'none'; //or
link.style.visibility = 'hidden';

Example 2: hide and show in angular 8

/* Component */
isShown: boolean;

ngOnInit(){
  isShown = false; //hidden every time subscribe detects change
}

toggleShow() {
  this.isShown = ! this.isShown;
}

/* Template */
<div *ngIf="isShown" class="row container-fluid" id="divshow">
  content
</div>