title: PHP - isset($variable) and notices
body: <p>so if I have this code:</p>
  
  <pre><code>$bla = 1;    
  if($foo &amp;&amp; $bla) do_whatever...
  </code></pre>
  
  <p>I get a notice telling me that <code>$foo</code> is a undefined variable.</p>
  
  <p>So I have to change my code to this:</p>
  
  <pre><code>$bla = 1;
  if(isset($foo) &amp;&amp; $foo &amp;&amp; $bla) do_whatever...
  </code></pre>
  
  <p>Is there anyway I can avoid checking if a variable is assigned and just assume the variable is false, but without having to turn off PHP notices?</p>