backreference

问题 I want to use the $1 value like an integer. The idea is to replace all numbers from originaltext with the equivalent array values and create a new text. The below desired outcome should be "This is DBValue4, This is DBValue2, This is DBValue7" Also, is there a way to save these backreferences for further use? String[] values = {"DBValue0","DBValue1","DBValue2","DBValue3","DBValue4","DBValue5","DBValue6","DBValue7","DBValue8","DBValue9","DBValue10"}; String originaltext = "This is 4, This is 2

问题 Consider (\w[0-9]).*\1 RegEx, it matches to d1akdhfafd1 , R2ddsfasfasfdsfdR2 , etc. . Is is possible to write a RegEx that that match to following too: D1dfsadfadsfE3 , z6adfdasfdfr2 , e3654654e0 ,....? \w[0-9] is just an example, please consider general form (::A_Complex_Pattern::).*\1 回答1: PHP's regex engine (PCRE) supports recursion. A few others do, but you generally shouldn't count on it. However, if the engine does, then you can insert patterns used elsewhere like this: (\w\d).*(?1)

问题 i wonder what is the problem with the backreference here: preg_match_all('/__\((\'|")([^\1]+)\1/', "__('match this') . 'not this'", $matches); it is expected to match the string between __('') but actually it returns: match this') . 'not this any ideas? 回答1: Make your regex ungreedy: preg_match_all('/__((\'|")([^\1]+)\1/U', "__('match this') . 'not this'", $matches) 回答2: You can't use a backreference inside a character class because a character class matches exactly one character, and a

问题 I'm attempting this challenge: https://regex.alf.nu/4 I want to match all strings that don't contain an ABBA pattern. Match: aesthophysiology amphimictical baruria calomorphic Don't Match anallagmatic bassarisk chorioallantois coccomyces abba Firstly, I have a regex to determine the ABBA pattern. (\w)(\w)\2\1 Next I want to match strings that don't contain that pattern: ^((?!(\w)(\w)\2\1).)*$ However this matches everything. If I simplify this by specifying a literal for the negative

问题 I have a string S = '02143' and a list A = ['a','b','c','d','e'] . I want to replace all those digits in 'S' with their corresponding element in list A . For example, replace 0 with A[0] , 2 with A[2] and so on. Final output should be S = 'acbed' . I tried: S = re.sub(r'([0-9])', A[int(r'\g<1>')], S) However this gives an error ValueError: invalid literal for int() with base 10: '\\g<1>' . I guess it is considering backreference '\g<1>' as a string. How can I solve this especially using re

问题 In SQL Server 2008, I have built a regex match and replace function from below code project site and is working well. http://www.codeproject.com/KB/string/SqlRegEx.aspx?msg=3683405#xx3683405xx. This functions basically looks up column text, finds match and replaces with the replaced text. I have used back reference here. e.g. if Column1 had 'the first article #345 is refered by 9999 and place in 001', it will return 345#9999#001 The select statement Select column1, dbo.ufn_RegExReplace

问题 I need to do some very light parsing of C# (actually transpiled Razor code) to replace a list of function calls with textual replacements. If given a set containing {"Foo.myFunc" : "\"def\"" } it should replace this code: var res = "abc" + Foo.myFunc(foo, Bar.otherFunc( Baz.funk())); with this: var res = "abc" + "def" I don't care about the nested expressions. This seems fairly trivial and I think I should be able to avoid building an entire C# parser using something like this for every

问题 Normally we would write the following to replace one match: namesRegex = re.compile(r'(is)|(life)', re.I) replaced = namesRegex.sub(r"butter", "There is no life in the void.") print(replaced) output: There butter no butter in the void. What i want is to replace, probably using back references, each group with a specific text. Namely i want to replace the first group (is) with "are" and the second group (life) with "butterflies". Maybe something like that. But the following is not working code

问题 I'm trying to make a single pattern that will validate an input string. The validation rule does not allow any character to be repeated more that 3 times in a row. For example: Aabcddee - is valid. Aabcddde - is not valid, because of 3 d chracters. The goal is to provide a RegExp pattern that could match one of above examples, but not both. I know I could use back-references such as ([a-z])\1{1,2} but this matches only sequential characters. My problem is that I cannot figure out how to make

问题 In a regex replacement pattern, a backreference looks like \1 . If you want to include a digit after that backreference, this will fail because the digit is considered to be part of the backreference number: # replace all twin digits by zeroes, but retain white space in between re.sub(r"\d(\s*)\d", r"0\10", "0 1") >>> sre_constants.error: invalid group reference Substitution pattern r"0\1 0" would work fine but in the failing example back-reference \1 is interpreted as \10 . How can the digit