title: exact array using ES 6 from an array of object
body: <p>I'm working with Angular 5 http Client to fetch data from an API. This is my subscribe part </p>
  
  <pre><code>vehicles: Vehicle[];
  getVehicleList() {
  this.vehicleService.getVehicleData()  
  .subscribe(data =&gt; { 
      this.vehicles = data
      console.log(JSON.stringify(data));} 
  )
  }
  </code></pre>
  
  <p>Vehicle interface</p>
  
  <pre><code>  export interface Vehicle {
      type: string;
   } 
  </code></pre>
  
  <p>I'm getting an JSON look like this</p>
  
  <pre><code>       {
    "data": [
      {
        "type": "bus"
      },
      {
        "type": "truck"
      },
      {
        "type": "car"
      }
    ],
    "_metadata": null
  }
  </code></pre>
  
  <p>I want to get only array from above using map function. Could someone help me with this?</p>