<h1>title 1</h1 w:id="0"/><p>content</p><h1>title 2</h1 w:id="1"/>...
I want to replace w:id="0"/ from </h1 w:id:="0 or 1 ect "/>
I use this code:
preg_replace("</h1 (.*?)>",'',$html)
But it doesn't work anymore
You are missing the delimiters on your regex.
A regex needs a 'starting mark' and a similar 'finishing mark', so PHP can interpret it's content as the match, with all it's flags.
Without the recognized delimiters, it's impossible to diferenciate between simple text and a regex.
Try this regex:
@</h1 (.*?)>@
Or:
~</h1 (.*?)>~
PHP supports a few more delimiters, like <> and /.
As a side note, I would suggest the following regex:
~</h1( [^>]+)?>~i
try this
preg_replace("/<\/h1 (.*?)>/i",'</h1>',$html);