title: Angular2 EXCEPTION No provider for String
body: <p>I've got a brand new app create with a ng-cli
  with this very simple code ^^</p>
  
  <pre><code>import { Component } from '@angular/core';
  
  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
  })
  export class AppComponent {
    constructor(private my: string) {}
  } 
  </code></pre>
  
  <p>and I've got in the console</p>
  
  <p><strong>EXCEPTION: No provider for String!</strong></p>
  
  <p>I don't see any error in the code so
  what's wrong !</p>
  
  <p>In ng-book I can read</p>
  
  <pre><code>export class Article { 
    title: string; 
    link: string; 
    votes: number;
    constructor(title: string, link: string, votes?: number) { 
      this.title = title;
      this.link = link;
      this.votes = votes || 0;
    }
  }
  </code></pre>
  
  <h2>Take a look at</h2>
  
  <p><a href="https://github.com/Microsoft/TypeScriptSamples/blob/master/greeter/greeter.ts" rel="noreferrer">https://github.com/Microsoft/TypeScriptSamples/blob/master/greeter/greeter.ts</a></p>