Regular Expressions
Regex.IsMatch(input, regex[, RegexOptions.Multiline]);
Match m = Regex.Match(input, regex);
m.Groups[i];
while(m.Success) {
m.NextMatch();
m.Result(replaceExpression);
Regex.Replace(input, regex, replaceExpression);
}
RegexOptions
| RegexOptions.None | |
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| RegexOptions.IgnoreCase | (i) |
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| RegexOptions.Multiline | Changes meaning of ^ and $ to match beginning and end of each line rather than whole string. |
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| RegexOptions.ExplicitCapture | (n) - Specifies that the only valid captures are explicitly named or numbered groups of the form (?&nblt;name&nbgt;?). This allows unnamed parentheses to act as noncapturing groups without the syntactic clumsiness of the expression (?:?). |
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| RegexOptions.Compiled | Specifies that the regular expression is compiled to an assembly. This yields faster execution but increases startup time. |
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| RegexOptions.SingleLine | (s) - . matches \n |
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| RegexOptions.IgnorePatternWhitespace | (x) and allows comments marked with # |
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| RegexOptions.RightToLeft | |
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| RegexOptions.CultureInvariant | Specifies that cultural differences in language is ignored. |
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MetaCharacters
| ^ | start (of each line if multiline) |
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| $ | end (of each line if multiline) |
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| \A | absolute start |
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| \Z | absolute end (ignoring last \n) |
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| \z | absolute end |
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| \G | match after where last match ended |
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| \b | word boundary (between \w & \W) |
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| \B | non-word boundary |
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| \t | tab |
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| \x20 | ASCII |
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| \cC | Control C |
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| \u0020 | Unicode |
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| * | 0-∞ |
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| + | 1-∞ |
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| ? | 0-1 |
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| {n} | Match n times |
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| {n,m} | Match between n and m times |
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| The above appended with ? | Non-greedy |
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| . | Anything but \n |
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| x|y | x or y |
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| [xyz] | |
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| [a-z] | |
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| \d | digit |
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| \D | non-digit |
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'| \s | white space character |
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| \S | non-white space character |
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| \w | [A-Za-z0-9_] |
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| \W | Opposite of \w |
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| (?:[xyz]) | Non-capturing |
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| (?<groupName>[xyz]) | named group |
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| (?<myGroup>\s\w+)\k<myGroup> | Backreference, matches "the the", "the theory" |
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Substitutions
\1 matches first group
$n
${name}
$$ - $ sign