date formate check

<?php
$format =array('m','d','y');
$strDate = date("m-d-Y");
$ex = "-";
echo isValidDate($strDate,$format,$ex);
function isValidDate($strDate,$format,$ex) {
      $valid = false;
      if(is_array($format) && count($format) == 3 && count(explode($ex,$strDate))==3)
      {
         $date = array_combine($format,explode($ex,$strDate));
         //print_r($date);
         if(intval($date['m']) && intval($date['d']) && intval($date['y'])){
           $m = $date['m']; $d = $date['d']; $y = $date['y'];
            $valid = checkdate($m,$d,$y);
         }
      }
      return $valid;
   }
?>