Now, let's play around with the files we already have. Navigate to the app/ch4/ts/hello-world directory inside getting-started-with-angular. Then, open app.ts and replace its content with the following snippet:

// ch4/ts/hello-world/app.ts 
 
import {Component, NgModule} from '@angular/core';
import {BrowserModule} from '@angular/platform-browser';
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';

@Component({
  selector: 'my-app',
  templateUrl: './app.html'
})
class App {
  target: string;
  constructor() {
    this.target = 'world';
  }
}

@NgModule({
  declarations: [App],
  imports: [BrowserModule],
  bootstrap: [App],
})
class AppModule {}

platformBrowserDynamic().bootstrapModule(AppModule);

Let's take a look at the code line by line:

import {Component, NgModule} from '@angular/core';
import {BrowserModule...