Question

How can I alter this callback so that it sends matches on the keyword “test” in all cases where there is not a “>” character preceeding the keyword? And only matches on the whole word, (ie, does not match on “testing”)

$theContent = preg_replace_callback("/\b('test')\b/i","doReplace", $content);

Answer 1

With a negative lookbehind:

/\b(?<!>)(test)\b/