import { BrowserModule } from '@angular/platform-browser';
 
 @NgModule({

  imports: [
    BrowserModule,
  ]
})
export class AppModule { }

import { NgModule } from '@angular/core';
// BrowserModule automatically imports all CommonModule Dependencies
  
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
  
@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    // Adding Imports
    BrowserModule,
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

import { Component, OnInit } from '@angular/core';
  
@Component({
    selector: 'app-root',
    templateUrl: './app.component.html'
})
export class AppComponent {
    geek = "GeekClass";
    g = document.getElementsByClassName(this.geek);
}

<!-- use of ngClass directive -->
<h1 [ngClass] = "geek">
  GeeksforGeeks
</h1>
  Upper Heading's class is : "{{ g[0].className }}"