Help with coding

[sidsel]

I have this "dirty" phpcode here which I try to rewrite to a more professional way but I can't find the "key" :

if ($row["imagestotal"] <= 6) {

$cells = 6;									

} else {

if (($row["imagestotal"] == 7) || ($row["imagestotal"] == 8)) {
$cells = 4;									

} elseif (($row["imagestotal"] == 9) || ($row["imagestotal"] == 10) || ($row["imagestotal"] == 13) || ($row["imagestotal"] == 14) || ($row["imagestotal"] == 15) || ($row["imagestotal"] == 19) || ($row["imagestotal"] == 20)) {
$cells = 5;									

} elseif (($row["imagestotal"] == 11) || ($row["imagestotal"] == 12) || ($row["imagestotal"] == 16) || ($row["imagestotal"] == 17) || ($row["imagestotal"] == 18)) {
$cells = 6;									

}

}

$rows = ceil($row["imagestotal"] / $cells);

[laserlight]

well, 1 possible way to rewrite it would be to use a switch, say:

switch ($row["imagestotal"]) {
case 7:
case 8:
	$cells = 4; break;
case 9:
case 10:
case 13:
case 14:
case 15:
case 19:
case 20:
	$cells = 5; break;
case 11:
case 12:
case 16:
case 17:
case 18:
	$cells = 6; break;
default: /* assume $row["imagestotal"] <= 6 */
	$cells = 6;
}

$rows = ceil($row["imagestotal"] / $cells);

of course you could also initialise $cells to 6 before the switch and leave out the default case.
You can even treat the {11, 12, 16, 17, 18} set as default as well, though that might be bad if not well documented.