Share data between components

share-data.service.ts

import { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class SharedDataService {

  private headerId: BehaviorSubject<number> = new BehaviorSubject<number>(0);

  constructor() { }

  setHeaderId(headerId: number) {
    this.headerId.next(headerId);
  }

  getHeaderId() {
    return this.headerId.getValue();
  }

}