split string into groups

[fraction]

I have this string:
$string='1,2,3,4,5,6,7,8,9,10,...100...?';

I want to group by 25

I have tried split but i cant figure out how to group my results by 25 variables. My problem is that my string will always be a different amount of variables, but i will always want to group by 25. Any help please.

TIA

[jimsonchang]

<?
$str_problem = "1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102";
$str_problem_alone = explode(",", $str_problem);
$str_problem_counter = 0;

$str_group = sizeof($str_problem_alone)/25;
$str_remain = sizeof($str_problem_alone)%25;

settype($str_group, "string");
$str_group = explode(".", $str_group);
(int) $str_group[0];

for($i=1; $i<=25; $i++)
{
if($i!=25)
{
$group[$i] = "";

	for($j=0; $j<$str_group[0]; $j++, $str_problem_counter++)
	{
		$group[$i]	=	$group[$i].$str_problem_alone[$str_problem_counter].", ";
	}

} else {
	while($str_problem_counter<sizeof($str_problem_alone)){
		$group[$i]	=	$group[$i].$str_problem_alone[$str_problem_counter].", ";
		$str_problem_counter++;
	}
}

}

for($i=1; $i<=25; $i++){
echo "<b>group $i : </b>";
echo $group[$i];
echo "<br>";
}
?>

[jimsonchang]

this is what i understand from ur question
if something miss. please detail ur question to ease me... 🙂
the output of the program

group 1 : 1, 2, 3, 4,
group 2 : 5, 6, 7, 8,
group 3 : 9, 10, 11, 12,
group 4 : 13, 14, 15, 16,
group 5 : 17, 18, 19, 20,
group 6 : 21, 22, 23, 24,
group 7 : 25, 26, 27, 28,
group 8 : 29, 30, 31, 32,
group 9 : 33, 34, 35, 36,
group 10 : 37, 38, 39, 40,
group 11 : 41, 42, 43, 44,
group 12 : 45, 46, 47, 48,
group 13 : 49, 50, 51, 52,
group 14 : 53, 54, 55, 56,
group 15 : 57, 58, 59, 60,
group 16 : 61, 62, 63, 64,
group 17 : 65, 66, 67, 68,
group 18 : 69, 70, 71, 72,
group 19 : 73, 74, 75, 76,
group 20 : 77, 78, 79, 80,
group 21 : 81, 82, 83, 84,
group 22 : 85, 86, 87, 88,
group 23 : 89, 90, 91, 92,
group 24 : 93, 94, 95, 96,
group 25 : 97, 98, 99, 100, 101, 102,

any reply, please send to
[e-mail]

omit the "nono".

sincerely,
Jimson Chang