title: Angular 4 Component of sub module is not working when using in root/main module
body: <p>I have a angular module (@ngModule) named SubModule which contains a component named SubComponent with css selector 'app-subcomp'.</p>
  
  <p>I have imported this sub module into my AppModule (application shell). So my AppModule (@ngModule) contains AppComponent with 'app-root' css selector and one sub module (SubModule). </p>
  
  <p>When i write '&lt; app-subcomp >' into my app.component.html, it is not rendering sub.component.html.</p>
  
  <p>but when i directly declare my SubComponent into AppModule, its working  fine.</p>
  
  <p>Not sure why it is not rendering in first case?</p>
  
  <p>Please  suggest.</p>
  
  <p>Thank You</p>
  
  <p><strong>sub.module.ts</strong></p>
  
  <pre><code>import { NgModule } from '@angular/core'; 
  import { CommonModule } from '@angular/common'; 
  import { SubComponent } from './sub.component'; 
  
  @NgModule({ 
       imports: [ CommonModule ], 
       declarations: [SubComponent], 
  }) 
  export class SubModule { }
  </code></pre>