title: How to quickly Comment and uncomment a code?
body: <p>Sometimes I have the need to try: A code example or a variant of it.<br>
      This is necessary to test a new functionality or to test its implementation or performance.
      The code can be very long.<br>
  So I need some way to quickly comment on the code with  </p>
  
  <pre><code>/*  
   * mi código  
   * …  
   * /
  </code></pre>
  
  <p>O con: </p>
  
  <pre><code>//  
  // mi código  
  // …  
  //
  </code></pre>
  
  <p>When the code is very long, it is cumbersome to do: Select all the code you do not want to run and discuss, Write or insert the code you want to try, Do tests or whatever...<br>
  Now...<br>
    Select and comment on the new block of code.<br>
    Search and select the previous code, and Uncomment.<br>
    Do tests or whatever...<br>
  And so I need to do it many times since I'm recycling, as I have been thirty years since I program almost nothing.  </p>
  
  <p>Is There any way or trick to do it quickly?</p>