How can I put characters around a word which begins with a specific character?

Question

For example I have a string : "This is a !thing"

How can I make it like this - "This is a !<b>thing</b>"

Any help would be appreciated.

Thanks guys.

Answer 1

preg_replace('/!(\w+)/', '!<b>$1</b>', $string);

In the replacement string $n is replaced with whatever matched nth capture group in the regexp.