title: RxJS: Observable.create() vs. Observable.from()
body: <p>What's the difference between these two?</p>
  
  <pre><code>return Observable.create(function(observer) {
      if (array)
          observer.next([]);
      else
          observer.next(null);
      observer.complete();
  });
  </code></pre>
  
  <p>and </p>
  
  <pre><code>return Observable.from( array ? [] : null );
  </code></pre>
  
  <p>I thought it could be the same but didn't work the same.</p>