title: RxJava: dynamically create Observables and send the final resut as Observable
body: <p>I am using RxJava in which I want to dynamically create a number of Observables based on some condition. Once I'm done with creating, I want to do some processing on the different values returned by the observables and then send as a single Observable to which I can subscribe on. Here is how my code is :</p>
  
  <pre><code>List&lt;String&gt; valueList = .... 
  
  List&lt;Observable&lt;String&gt;&gt; listOfObservables = new ArrayList&lt;Observable&lt;String&gt;&gt;();
  
  for(int i =; i &lt;valueList.size(); i++){
          listOfObservables.add(new SomeClass.doOperation(valueList(i)));
          // SomeClass.doOperation will return an Observable&lt;String&gt;
      }
  
  return Observable.merge(listOfObservables);
  </code></pre>
  
  <p>But here , I want to do some operation on the values emitted by different Observables in the <code>listOfObservable</code> and finally return it as a single <code>Observable&lt;String&gt;</code></p>
  
  <p>Like in <code>Observable.zip()</code> , I can do this like </p>
  
  <pre><code>return Observable.zip(observable1, observable2, (string1, string2) -&gt; {
              // joining final string here
              return string1 + string2;
  </code></pre>
  
  <p>But I know the number of arguments here. Please let me know how I can achieve this.</p>