RegexOptions Enumeration
Provides enumerated values to use to set regular expression options.
This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.
Namespace: System.Text.RegularExpressionsAssembly: System (in System.dll)
| Member name | Description | |
|---|---|---|
![]() ![]() | None | Specifies that no options are set. |
![]() ![]() | IgnoreCase | Specifies case-insensitive matching. |
![]() ![]() | Multiline | Multiline mode. Changes the meaning of ^ and $ so they match at the beginning and end, respectively, of any line, and not just the beginning and end of the entire string. |
![]() ![]() | ExplicitCapture | Specifies that the only valid captures are explicitly named or numbered groups of the form (?<name>…). This allows unnamed parentheses to act as noncapturing groups without the syntactic clumsiness of the expression (?:…). |
![]() | Compiled | Specifies that the regular expression is compiled to an assembly. This yields faster execution but increases startup time. This value should not be assigned to the Options property when calling the CompileToAssembly method. |
![]() ![]() | Singleline | Specifies single-line mode. Changes the meaning of the dot (.) so it matches every character (instead of every character except \n). |
![]() ![]() | IgnorePatternWhitespace | Eliminates unescaped white space from the pattern and enables comments marked with #. However, the IgnorePatternWhitespace value does not affect or eliminate white space in character classes. |
![]() ![]() | RightToLeft | Specifies that the search will be from right to left instead of from left to right. |
![]() ![]() | ECMAScript | Enables ECMAScript-compliant behavior for the expression. This value can be used only in conjunction with the IgnoreCase, Multiline, and Compiled values. The use of this value with any other values results in an exception. |
![]() ![]() | CultureInvariant | Specifies that cultural differences in language is ignored. See Performing Culture-Insensitive Operations in the RegularExpressions Namespace for more information. |
A RegexOptions value can be provided as a parameter to the following members of the Regex class:
The Regex::Regex(String, RegexOptions) class constructor.
The Regex::Split(String, String, RegexOptions) method.
The Regex::IsMatch(String, String, RegexOptions) method.
The Regex::Match(String, String, RegexOptions) method.
The Regex::Matches(String, String, RegexOptions) method.
The Regex::Replace(String, String, String, RegexOptions) and Regex::Replace(String, String, MatchEvaluator, RegexOptions) methods.
A RegexOptions value can also be supplied as a parameter to the RegexCompilationInfo constructor, or it can be assigned directly to the Options property. The resulting RegexCompilationInfo object is then used in the call to the CompileToAssembly method.
Several options provided by members of the RegexOptions enumeration (in particular, by its RegexOptions::ExplicitCapture, RegexOptions::IgnoreCase, RegexOptions::Multiline, and RegexOptions::Singleline members) can instead be provided by using an inline option character in the regular expression pattern. For details, see Regular Expression Options.
The following example defines two regular expressions that identify repeated words in text but that are instantiated using different RegexOptions values. The first regular expression is case-insensitive; case is ignored when determining whether a word is identical to the preceding word. The second regular expression is case-sensitive; a word must match the case of the preceding word exactly to be considered a duplicate.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

