Skip to content

Fix RegexOptions.ECMAScript combinations #49453

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Oct 28, 2025
+1 −1
Merged

Fix RegexOptions.ECMAScript combinations #49453

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion docs/standard/base-types/regular-expression-options.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -333,7 +333,7 @@ By default, the regular expression engine uses canonical behavior when matching
> [!NOTE]
> ECMAScript-compliant behavior is available only by supplying the <xref:System.Text.RegularExpressions.RegexOptions.ECMAScript?displayProperty=nameWithType> value to the `options` parameter of a <xref:System.Text.RegularExpressions.Regex> class constructor or static pattern-matching method. It is not available as an inline option.

The <xref:System.Text.RegularExpressions.RegexOptions.ECMAScript?displayProperty=nameWithType> option can be combined only with the <xref:System.Text.RegularExpressions.RegexOptions.IgnoreCase?displayProperty=nameWithType> and <xref:System.Text.RegularExpressions.RegexOptions.Multiline?displayProperty=nameWithType> options. The use of any other option in a regular expression results in an <xref:System.ArgumentOutOfRangeException>.
The <xref:System.Text.RegularExpressions.RegexOptions.ECMAScript?displayProperty=nameWithType> option can be combined only with the <xref:System.Text.RegularExpressions.RegexOptions.IgnoreCase?displayProperty=nameWithType>, <xref:System.Text.RegularExpressions.RegexOptions.Multiline?displayProperty=nameWithType>, and <xref:System.Text.RegularExpressions.RegexOptions.Compiled?displayProperty=nameWithType> options. The use of any other option in a regular expression results in an <xref:System.ArgumentOutOfRangeException>.

The behavior of ECMAScript and canonical regular expressions differs in three areas: character class syntax, self-referencing capturing groups, and octal versus backreference interpretation.

Expand Down
Loading