Returns the regular expression pattern that was passed into the Regex constructor.
Assembly: System (in System.dll)
The pattern parameter consists of regular expression language elements that symbolically describe the string to match. For more information about regular expressions, see .NET Framework Regular Expressions and Regular Expression Language - Quick Reference.Notes to Inheritors
Regex is the base class of regular expressions created by the CompileToAssembly method. These compiled regular expressions use the implementation of the base class. If called from a derived class, the method returns the string that was passed to the pattern parameter of the RegexCompilationInfo class constructor that was used to define the regular expression.