PHP 5.3闭包语法初探

 $closure = function($param) { echo $param; };

 //This one takes value of someVar and "stores" it in the closure's scope even if
 
 //we later change the value of someVar outside it.

     // We assume that $somerVar is defined before this
 
 $closure2 = function($param) use ($someVar) { echo $param . ' ' . $someVar; };

function item_list(array $items, $formatter = null) {   
   //create the default formatter   
   if($formatter == null) {   
     $formatter = function($row) {   
       return '﹤p﹥' . $row . '﹤/p﹥';   
     };   
   }   
     
   $html = '﹤h2﹥Listing:﹤/h2﹥';   
   foreach($items as $item) {   
     $html .= $formatter($item);   
   }   
     
   return $html;   
 }