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Matches any character not in the specified range. For example, "" matches any lowercase alphabetic character in the range a through z.Ī negative range characters. Matches any character in the specified range. For example, matches the p in plain.Ī range of characters. For example, matches the a in plain.Ī negative character set. Matches any one of the enclosed characters. For example, o is equivalent to o?.Ī character set. If you need to include the parentheses characters into a subexpression, use \( or \). If you need to refer the matched substring somewhere outside the current regular expression (for example, in another regular expression as a replacement string), you can retrieve it using the dollar sign $num, where num = 1.n. If you need to use the matched substring within the same regular expression, you can retrieve it using the backreference \num, where num = 1.n. Thus a regex operator can be applied to the entire group. If a part of a regular expression is enclosed in parentheses, that part of the regular expression is grouped together. Matches subexpression and remembers the match. Matches any single character except a newline character. For example, a?ve? matches the ve in never. Matches the preceding character zero or one time. For example, "zo+" matches zoo but not z. Matches the preceding character one or more times. For example, "zo*" matches either z or zoo. Matches the preceding character zero or more times. The sequence \\ matches \ and \( matches (. For example, you can use the replacement string $", value, Regex.Marks the next character as either a special character or a literal. If this is not your intent, you can substitute a named group instead. For more information about numbered capturing groups, see Grouping Constructs.Īll digits that follow $ are interpreted as belonging to the number group. For example, the replacement pattern $1 indicates that the matched substring is to be replaced by the first captured group. The $ number language element includes the last substring matched by the number capturing group in the replacement string, where number is the index of the capturing group.
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For more information about backreferences, see Backreference Constructs. In a replacement pattern, $ indicates the beginning of a substitution.įor functionality similar to a replacement pattern within a regular expression, use a backreference. In a regular expression pattern, $ is an anchor that matches the end of the string. The only character that can appear either in a regular expression pattern or in a substitution is the $ character, although it has a different meaning in each context. Similarly, substitution language elements are recognized only in replacement patterns and are never valid in regular expression patterns. ), which matches any character, are supported. None of the other regular expression language elements, including character escapes and the period (. Substitutions are the only special constructs recognized in a replacement pattern. Substitution Elements and Replacement Patterns
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For more information, see Substituting the Entire Input String. Includes the entire input string in the replacement string. For more information, see Substituting the Last Captured Group. Includes the last group captured in the replacement string. For more information, see Substituting the Text after the Match. Includes all the text of the input string after the match in the replacement string. For more information, see Substituting the Text before the Match. Includes all the text of the input string before the match in the replacement string. For more information, see Substituting the Entire Match. Includes a copy of the entire match in the replacement string. For more information, see Substituting a "$" Symbol. Includes a single "$" literal in the replacement string. For more information, see Substituting a Named Group. Includes the last substring matched by the named group that is designated by (? ) in the replacement string. For more information, see Substituting a Numbered Group. Includes the last substring matched by the capturing group that is identified by number, where number is a decimal value, in the replacement string. NET defines the substitution elements listed in the following table. The methods replace the matched pattern with the pattern that is defined by the replacement parameter. Replacement patterns are provided to overloads of the Regex.Replace method that have a replacement parameter and to the Match.Result method. The replacement pattern can consist of one or more substitutions along with literal characters. They use a regular expression pattern to define all or part of the text that is to replace matched text in the input string. Substitutions are language elements that are recognized only within replacement patterns.