title: Warning: filter_var() expects parameter 2 to be long, string given in
body: <p>In this code I get a warning</p>
  
  <p>Warning: filter_var() expects parameter 2 to be long, string given in the last line</p>
  
  <pre><code>$check = filter_var($email, FILTER_SANITIZE_EMAIL);
  $str = filter_var($name, FILTER_SANITIZE_STRING);
  if (!filter_var($check, FILTER_VALIDATE_EMAIL) &amp;&amp; !filter_var($str, FILTER_VALIDATE_STRING)) { //here
  </code></pre>
  
  <p>The problem is this, because without it no exists any warning message </p>
  
  <pre><code> !filter_var($str, FILTER_VALIDATE_STRING)
  </code></pre>
  
  <p>What is the reason of this error?</p>