Regular expression!

[alimadhi]

I have a string like this:

Something A something something B something
C something D .....
I want to extract (i.e put in an array)
only A, B, C, D and remove everything else
How can I do that?

Thank you

Ferdinand.

[Anon]

why would you want to do that?

if you just want to see if A, B, C, D etc is in the string, u can just use substr(count) like this:

if (substr_count($str, 'A')) {
//A in string
}

etc etc

Otherwise i cant see a reason why youd need to do that

[alimadhi]

Thank you for your fast reply!

I know that let say there are 15 A,B,C or D in my string.But I would like to know the order of them from the begininng of the string.
That's why I was thinking to remove everything else from the string and then do an explode() to have them in an array or
directly take them from the string one by one (in order)!!!

Ferdinand.

[Anon]

ok lets see....

//$s is your string
//Set first strposes
$A = strpos($s, 'A');
$B = strpos($s, 'B');
$C = strpos($s, 'C');
$D = strpos($s, 'D');
while ($A || $B || $C || $D) {

if ($A < ($B && $C && $D)) {
//$A is lowest
$new .= 'A';
$s = substr($s, $A);
} else if ($B < ($C && $D)) {
//$B is lowest
$new .= 'B';
$s = substr($s, $😎;
} else if ($C < $D) {
//$C is lowest
$new .= 'C';
$s = substr($s, $C);
} else {
//$D is lowest
$new .= 'D';
$s = substr($s, $D);
}
$A = strpos($s, 'A');
$B = strpos($s, 'B');
$C = strpos($s, 'C');
$D = strpos($s, 'D');
}

that should do it. there might be a function in php to tell if which is lowest though