title: Can't assign value to variable using subscribe() method in Angular 2
body: <p>The promise returns a value but I don't seem to be assigning the value properly in the subscribe method. </p>
  
  <pre><code>import { Component } from '@angular/core';
  import { DataService } from '../../shared/data.service';
  
  @Component({
    selector: 'topbar',
    templateUrl: './src/app/components/topbar/topbar.component.html',
    styleUrls: ['./src/app/components/topbar/topbar.component.css'],
    providers: [DataService]
  })
  
  export class TopbarComponent {
    companyCount;
  
    constructor (private dataService: DataService){
      dataService.getCompaniesCount().subscribe(res =&gt; this.companyCount = res.count); //doesn't work
      dataService.getCompaniesCount().subscribe(res =&gt; console.log(res.count)); //works    
    }
  }
  </code></pre>