preg_replace how to replace only matching xxx($1)yyy pattern inside the selector

php regex replace preg-match regex-group

Use backreferences (i.e. brackets) to keep only the parts of the expression that you want to remember. You can recall the contents in the replacement string by using $1, $2, etc.:

preg_replace('/(text1)text2(text3)/is','$1$2',$html);

php regex replace preg-match regex-group

There is an alternative to using text1 and text3 in the match pattern and then putting them back in via the replacement string. You can use assertions like this:

preg_replace('/(?<=text1)(text2)(?=text3)/', "", $txt);

This way the regular expression looks just for the presence, but does not take the two strings into account when applying the replacement.

http://www.regular-expressions.info/lookaround.html for more information.

php regex replace preg-match regex-group

Try this:

$text = preg_replace("'(text1)text2(text3)'is", "$1$2", $text);

Hope it works!

Edit: changed \\1\\2 to $1$2 which is the recommended way.