sorting array

Anon

Pardon my sloppy explanation but here it is:

how can i sort an array based on key element ie.

key values are: a1, a2 ,a3 ..., b1, b2 ,b3, ...c1, c1, c3...
so doing this:
while (list($k, $v) = each($formdata)) {
for ($i=0; $i<count($k); $i++) {
echo "$k[0] = $v\n<br>";
}
will list all the $k $v .

Now, how can i sort it according to $k[0]
where $k[0] = a, than the same for all b's and so on?

Anon

just use ksort()

<?
ksort ($array);
foreach ($array as $key => $value) {
echo "$key = $value<br>";
}
?>

Anon

great, but what i'm interested in doing is running a test for all keys grouped into categories based on the first letter ie. a1, a2, a3, ...b1, b2.
so only a and b and so on is of any interest.
let's say
if ($key == $value){ $error = 1;

Anon

if still not quite sure what you are asking

<?
foreach ($array as $key => $value) {
if (substr ($key, 0, 1) == 'a') {
... do something with the a's...
}
}
?>

repeat as necessary for b,c, etc...

Anon

yes, you're right
substr, or what i actually tried was

$A = strstr ($k[$i], a);
echo "$A\n";

but your example does thing, as well.
In any case i'll have to repeat it for as meny times as i need

thx.