Initiating the same loop with either a while or foreach statement

I have code in php such as the following:

while($r = mysql_fetch_array($q))
{

// Do some stuff

}

where $q is a query retrieving a set of group members. However, certain groups have there members saved in memcached and that memcached value is stored in an array as $mem_entry. To run through that, I'd normally do the following

foreach($mem_entry as $k => $r)
{

// Do some stuff

}

Here's the problem. I don't want to have two blocks of identical code (the //do some stuff section) nested in two different loops just because in one case I have to use mysql for the loop and the other memcached. Is there some way to toggle starting off the loop with the while or foreach? In other words, if $mem_entry has a non-blank value, the first line of the loop will be foreach($mem_entry as $k => $r), or if it's empty, the first line of the loop will be while($r = mysql_fetch_array($q))

Edit

Well, pretty much a few seconds after I wrote this I ended up coming with the solution. Figure I'd leave this up for anyone else that might come upon this problem. I first set the value of $members to the memcached value. If that's blank, I run 开发者_如何学Gothe mysql query and use a while loop to transfer all the records to an array called $members. I then initiate the loop using foreach($members as as $k => $r). Basically, I'm using a foreach loop everytime, but the value of $members is set differently based on whether or not a value for it exists in memcached.

Why not just refactor out doSomeStuff() as a function which gets called from within each loop. Yes, you'll need to see if this results in a performance hit, but unless that's significant, this is a simple approach to avoiding code repetition.

If there's a way to toggle as you suggest, I don't know of it.

Not the ideal solution but i will give you my 2 cents. The ideal would have been to call a function but if you dont want to do that then, you can try something like this:

if(!isset($mem_entry)){
 $mem_entry = array();
 while($r = mysql_fetch_array($q))
 {

   $mem_entry[] = $r;

 }
}

The idea is to just use the foreach loop to do the actual work, if there is nothing in memcache then fill your mem_entry array with stuff from mysql and then feed it to your foreach loop.