What's wrong with the regex for h1 tag search?

Question

PHP

$text="fhdsklf sdoijf ds <h1>jfidsfj</h1> jklsfdjflks";
$pattern ="!<h1>.+</h1>!";
preg_match($text, $pattern, $matches);
print_r($matches);

The code throws an error: "Warning: preg_match(): Delimiter must not be alphanumeric or backslash"

Answer 1

You need to swap $pattern and $text
Also I advise you to use .+? instead of .+, because otherwise, the regular expression will look for the last occurrence in the string.

$text="fhdsklf sdoijf ds <h1>jfidsfj</h1> jklsfdjflks";
$pattern ="!<h1>.+?</h1>!";
preg_match($pattern, $text, $matches);
print_r($matches);

Answer 2

Regulars and html parsing. Never do that. You have to use special. libraries, for example, here you can choose something. In general, it is better not to use regular games anywhere and never. They say using regular expressions you get two problems from one at once.