php regex strange error

Question

i use such regex $msg = preg_replace('/<b>(\\w)<\\/b>/', '9999', $msg); to replace <b>test</b> but it not replace. why?

Answer 1

You're missing the quantity token. That would only match one character long strings between the <b> tags.

$msg = preg_replace('/<b>(\w*)<\/b>/', '9999', $msg); 

Answer 2

尝试这个

$msg = preg_replace('#<b>(\w)*<\/b>#', '9999', $msg);

Answer 3

Your \\w does not match. I don't find my regex manual right now, but use something like .* .

Answer 4

注意\\ w +之后的加号

 $msg = preg_replace('/<b>(\w+)<\/b>/', '9999', $msg);