title: if inside a switch case, to restrict cases
body: <p>thanks for the answers. </p>
  
  <p>I would like to know if is it possible to restrict some cases of a swtich-case statement using conditional expressions. Like the code the follows. </p>
  
  <pre><code>switch(a)
  {
      case 1:
      {
          do_1();
          break;
      }
      case 2:
      {
          do_2();
          break;
      }
  
      if(condition)
      {
          case 3:
          {
              do_3();
              break;
          }
  
          break;
      }
  }
  </code></pre>
  
  <p>Edited, sorry guys, I got the wrong condition, it's not related at all with the switched variable. Just another condition, external one. 
  I just want to know if I can restrict the cases with an external conditions, otherwise, that cases inside the IF won't be analyzed if the condition is not satisfied.<br>
  Do I need the second break inside the if?</p>