Question

Is it possible to return a loop? not the result but the loop it self.
I want to create a function in php. For example like this.

function myloop($sql){
$query = mysql_query($sql);

return while(mysql_fetch_assoc($query))
}

The reason i want to create this is for me to avoid repeating code. Anyone can help me? Thank you..

Answer 1

No, you can’t. You can pass a function to a function, though:

// The myloop function, with another name.
function query($sql, $rowcallback)
{
  $query = mysqli_query($sql); // use mysqli, not mysql
  while 
    ( ($row = mysql_fetch_assoc($query)) &&
      call_user_func($rowcallback, $row) );
}

// The code to process a row.
function processRow(array $row)
{
   // Use your row here..
   var_dump($row);

   return true; // You can return false to break processing.
}

//calling:
query($yourSelf, 'processRow');

Instead of passing the function by name, you can also use anonymous functions, depending on your php version:

//calling:
query($yourSelf, 
  function(array $row)
  { 
    var_dump($row); 
    return true; // You can return false to break processing.
  });

The function which is called from the callee is often called a callback. call_user_func is the best way to call a callback, since it will also accept methods and static methods, not just functions, so you’re more flexible.