Regular expression to remove multiple parenthesis

问题

I'm in need of a regular expression that can remove unnecessary/extra parenthesis in a string if found.

Example:

Bob Barker LIVE! (((Don't Miss out!)))

Wanted Result:

Bob Barker LIVE! (Don't Miss out!)

I don't care if users you them, as long as they don't over use them, and make sure to close them.

Thanks for any feedback.

回答1:

That's easy enough.

preg_replace('~[\(\)]+~', '', $string);

Edit: I didn't read your whole question. You still want parenthesis, just not duplicates.

preg_replace(array('~\(+~', '~\)+~'), array('(', ')'), $string);

回答2:

You can do this effectively with regex + recursion. Do this until it stops doing anything:

s/\(\([^()]*)\)\)/\(\1\)/g

Now some comments:

1) I'm leaving it to you to convert sed/perl style into PHP style regex.

2) It's hard to read because ( ) are special characters. Basically I'm saying "replace every ((...)) with (...) as long as ... doesn't contain any ( or ). And to be honest I didn't test the mess I wrote down, but with this idea you should be able to repair.

This always removes them in pairs.

Basically the moral here is: you asked a question you can't do with a simple regex - removing in pairs requires more state than the language permits. But this one is low-hanging fruit if you iterate over the simple regex and eat the doubles from inside-out.

回答3:

Try this:

preg_replace( '/\(+(.*?)\)+/', '($1)', 'Bob Barker LIVE! (((Don\'t Miss out!)))');

Demo

回答4:

This won't work properly for nested parentheses, but that's really difficult to get right with regex (and depending on the engine even impossible):

preg_replace(array('/\(+/', '/\)+/'), array('(', ')'), $text);

回答5:

You can try this :

preg_replace("([\\(]{1,})", "(", preg_replace("([\\)]{1,})", ")", $your_string));

来源：https://stackoverflow.com/questions/10999835/regular-expression-to-remove-multiple-parenthesis

标签

php

regex

parentheses