title: How can I remove and add element on Array by index in RxJS way?
body: <p>So, I have a array of "events":</p>
  
  <pre class="lang-js prettyprint-override"><code>let events = Rx.Observable.from([1,2,3,4,5,6,7,8,9]);
  </code></pre>
  
  <p>I can add(push):</p>
  
  <pre class="lang-js prettyprint-override"><code>let add = function(number){
    events = events.concat([number]);
  }
  </code></pre>
  
  <p>I can remove:</p>
  
  <pre class="lang-js prettyprint-override"><code>let remove = function(){
    events = events.filter(event =&gt; {
    return event != 3;
  })
  }
  </code></pre>
  
  <p>My first question:
  How can I remove and add a element by index in "RxJS" way?</p>
  
  <pre class="lang-js prettyprint-override"><code>let removeByIndex = function(index){
    //remove by index
  }
  
  let addByIndex = function(index){
    //add by index
  }
  </code></pre>
  
  <p>My second question:
  I need "reinvent the wheel" for all basic methods of Array on RxJS from and of? </p>