title: how is #if / #endif different than if?
body: <p>I am following a tutorial that has this code:</p>
  
  <pre><code>    static void Main()
      {
          Application.EnableVisualStyles();
          Application.SetCompatibleTextRenderingDefault(false);
          int i = 1;
          while (true)
          {
  #if TEST
              if (i % 2 == 0)
              continue;
  #endif
              i++;
              Console.WriteLine("The value of i is {0}", i);
              if (i &gt; 9)
                  break;
              }
              Console.WriteLine("The value of i is {0}", i);
  
              Application.Run(new Form1());
          }
  </code></pre>
  
  <p>What is the purpose of using <code>#if TEST</code> instead of just <code>if(TEST)</code>?</p>