How to check if an object has options and display them?

Question

Angular

rielt: Object = { 
  buy: {
    name: 'Купить',
    thing: {
      room: {
        name: 'Room',
        options: {
          new: {
            name: 'NewHome'
          },
          secondhend: {
            name: 'SecondHend'
          }
        }
      },
      home: {
        name: 'Home'
      }
    }
  }, 
};

<mat-form-field>
    <mat-select [(ngModel)]="selected">
      <mat-option *ngFor="let n of rielt | keyvalue" [value]="n.key">
        {{ n.value.name }}
      </mat-option>
    </mat-select>
  </mat-form-field>

  <mat-form-field *ngIf="selected">
    <mat-select>
      <mat-option *ngFor="let n of rielt[selected].thing | keyvalue" [value]="n.key">
        {{ n.value.name }}
      </mat-option>
    </mat-select>
  </mat-form-field>

Let's say an object with the key room has options, but the home object doesn't.
I need to display the field according to the same analogy, but display it only if this key has options (let's say we will display them as a checkbox).

Answer 1

if I understand you correctly...