问题
I keep getting this error about 20 times in my wordpress blog about the same line of code. Here is the line of code that keeps getting the error.
if ( preg_match( '/' . $id_base . '-([0-9]+)$/', $widget_id, $matches ) )
$number = max($number, $matches[1]);
What could be wrong?
回答1:
Your regex will break if the string $id_base has a / in it as you are using / as the regex delimiter.
To fix this use preg_quote on $id_base as:
if (preg_match('/'. preg_quote($id_base,'/').'-([0-9]+)$/', .....) {
来源：https://stackoverflow.com/questions/5321068/warning-preg-match-function-preg-match-unknown-modifier-v