Demo Component

demo.component.ts

import { Component, OnInit, Input } from '@angular/core';
import { Subject } from 'rxjs';

@Component({
   selector: 'app-demo',
   templateUrl: './demo.component.html',
   styleUrls: ['./demo.component.scss']
})
export class Demo implements OnInit {
   
   statusUpdate = new Subject<boolean>();
   categoryUpdate: Subject<string>;
   userUpdate: Subject<number>;
   
   constructor() { 
      this.categoryUpdate = new Subject<string>();
   }
   
   ngOnInit() { 
      this.userUpdate = new Subject<number>();
   }

}