why should i reload the page to change the data in angular code example

Example: angular 6 reload current page

import { DOCUMENT } from '@angular/common';
import { Component, Inject } from '@angular/core';

@Component({
  selector: 'app-refresh-banner-notification',
  templateUrl: './refresh-banner-notification.component.html',
  styleUrls: ['./refresh-banner-notification.component.scss']
})

export class RefreshBannerNotificationComponent {

  constructor(
    @Inject(DOCUMENT) private _document: Document
  ) {}

  refreshPage() {
    this._document.defaultView.location.reload();
  }
}