title: rxjs: get last value from set of Observables
body: <p>I have 2 observable and I would like to have the value of the last one which emitted.</p>
  
  <p>Example:</p>
  
  <pre><code>private obs1: Observable&lt;number&gt; = interval(1000);
  private obs2: Observable&lt;number&gt; = interval(700);
  
  public lastValue; // should take the value of the last observable which emitted.
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/AYJ9G.jpg" rel="nofollow noreferrer">expected behavior</a></p>
  
  <p>I can't find the operator to use for this. One solution could be to subscribe to all observable, and then make lastValue a Subject and update its value with next, but I would like to avoid subscribing to all the observable.</p>
  
  <p>Thanks</p>