After strip_tags: <b onmouseover="alert(1)"b>
After regex: <b>
After strip_tags 2: <b onmouseover="alert(1)" > > > > > > >
After regex 2: <b> > > > > > >
After strip_tags 3: <b onmouseover="alert(1)" x="">test</b>
After regex 3: <b>test</b>