arrays - Get word from string

i trying extract word matches specific pattern various strings.

the strings vary in length , content.

for example:

i want extract word begins jac following strings , populate array full words:

the resulting array should [jacket,jack,jacksonville]

i have been trying use preg_match() reason won't work. suggestions???

$q = "jac"; $str = "jacket"; preg_match($q,$str,$matches);  print $matches[1];

this returns null :s. dunno problem is.

you can use preg_match as:

preg_match("/\b(jac.+?)\b/i", $string, $matches);

shell