How can you define a class that implements an interface via html?

Question

Angular

Hello.
There is an interface

export interfaces IFilter
{
   id : string
   description : string
   type: number
}

there are two classes

export class InputFilter impl IFilter
{
   id : string
   description : string
   inputString: string
   type: number
}

export class InputDate impl IFilter
{
   id : string
   description : string
   inputDate: string
   type: number
}

In the component, there is an array filters : IFilter[]

Why can't I access a property of the InputDate class like this, and how can I access it? Why doesn't html understand the instanceof check?

<div *ngFor="let filter of filters"> 
   <div *ngIf="type == 1">
    {{ filter.inputDate }}
  </div>
</div>

Answer 1

because implements only exists in typescript, as an aid to good advice to the programmer, and disappears at compilation.