NickName:Skwiggs Ask DateTime:2016-10-17T20:43:23

Regex - Match parentheses without matching their contents

I just need to match parentheses around some content that has to match specific criteria. I need to match only the parentheses so that I can then do a quick replacement of only those parentheses and keep their content.

For the moment, what I have matches those specific parentheses, but unfortunately also their contents: $(?:\d{2,7})$

The criteria for matching parentheses are as following:

only match parentheses that contain \d{2,7}

I have tried positive lookahead ($(?=\d{2,7})$), and while it does indeed not consume whatever follows the open parenthesis, it then fails to match the closing parenthesis as it backtracks to before the content...

So yeah, any help would be appreciated :)

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Link to original article：https://stackoverflow.com/questions/40086706/regex-match-parentheses-without-matching-their-contents

Answers

Phu Ngo 2016-10-17T12:55:54

Pure RegEx pattern: \$(?=\\d{2,7}\$)|(?<=\$)\\d{2,7}\\K\$\n\n\n\nUpdate: I don't know about Swift, but according to this documentation, Template Matching Format part, $n can also be used similarly, as in\n\nlet myString = \"(32) 123-323-2323\"\nlet regex = try! NSRegularExpression(pattern: \"\\\$(\\\\d{2,7})\\\$\")\nlet range = NSMakeRange(0, myString.characters.count)\nregex.stringByReplacingMatchesInString(myString,\n options: [],\n range: range,\n withTemplate: \"$1\")\n\n\n\n\nWith the assumption that you are using Java, I would suggest something as simple as\nstr.replaceAll(\"\\\$(\\\\d{2,7})\\\$\", \"$1\")\n\nThe pattern \$(\\d{2,7})\$ captures the whole expression with parantheses with the number in group 1 and replaces it with only the number inside, thus effectively removing the surrounding brackets.",

Jirka Picek 2016-10-17T12:54:49

The regex can be \$(\\d{2,7})\$. It will match all pairing parenthesis with content and the content is accessible via parameter 1 and can be added to string which replace the parenthesis.\n\nHow to access results of regex is language specific, I think.\n\nEDIT:\n\nHere is code which can work. It's untested and I have to warn you at first:\n\nThis is my first experience with Swift and online sandbox which I found couldn't compile it. But it couldn't compile examples from Apple website, either...\n\nimport Foundation\n\nlet text = \"some input 22 with (65498) numbers (8643)) and 63546 (parenthesis)\"\nlet regex = try NSRegularExpression(pattern: \"\\\$(\\\\d{2,7})\\\$\", options: [])\n\nlet replacedStr = regex.stringByReplacingMatchesInString(text, \n options: [], \n range: NSRange(location: 0, length: text.characters.count), \n withTemplate: \"$1\")\n",