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Match Class

Represents the results from a single regular expression match.

Namespace:  System.Text.RegularExpressions
Assembly:  System (in System.dll)

'Declaration
<SerializableAttribute> _
Public Class Match _
	Inherits Group

The Match type exposes the following members.

  NameDescription
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryCapturesGets a collection of all the captures matched by the capturing group, in innermost-leftmost-first order (or innermost-rightmost-first order if the regular expression is modified with the RegexOptions.RightToLeft option). The collection may have zero or more items. (Inherited from Group.)
Public propertyStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryEmptyGets the empty group. All failed matches return this empty match.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryGroupsGets a collection of groups matched by the regular expression.
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryIndexThe position in the original string where the first character of the captured substring was found. (Inherited from Capture.)
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryLengthThe length of the captured substring. (Inherited from Capture.)
Public propertySupported by the XNA FrameworkSupported by Portable Class LibrarySuccessGets a value indicating whether the match is successful. (Inherited from Group.)
Public propertySupported by the XNA FrameworkSupported by Portable Class LibraryValueGets the captured substring from the input string. (Inherited from Capture.)
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  NameDescription
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryNextMatchReturns a new Match object with the results for the next match, starting at the position at which the last match ended (at the character after the last matched character).
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryResultReturns the expansion of the specified replacement pattern.
Public methodStatic memberSupported by the XNA FrameworkSynchronizedReturns a Match instance equivalent to the one supplied that is suitable to share between multiple threads.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryToStringGets the captured substring from the input string. (Inherited from Capture.)
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The Match object is immutable and has no public constructor. An instance of the Match class is returned by the Regex.Match method and represents the first pattern match in a string. Subsequent matches are represented by Match objects returned by the Match.NextMatch method. In addition, a MatchCollection object that consists of zero, one, or more Match objects is returned by the Regex.Matches method.

If the Regex.Matches method fails to match a regular expression pattern in an input string, it returns an empty MatchCollection object. You can then use a foreach construct in C# or a For Each construct in Visual Basic to iterate the collection.

If the Regex.Match method fails to match the regular expression pattern, it returns a Match object that is equal to Match.Empty. You can use the Success property to determine whether the match was successful. The following example provides an illustration.


' Search for a pattern that is not found in the input string.
Dim pattern As String = "dog"
Dim input As String = "The cat saw the other cats playing in the back yard."
Dim match As Match = Regex.Match(input, pattern)
If match.Success Then
   ' Report position as a one-based integer.
   Console.WriteLine("'{0}' was found at position {1} in '{2}'.", _ 
                     match.Value, match.Index + 1, input)
Else
   Console.WriteLine("The pattern '{0}' was not found in '{1}'.", _
                     pattern, input)
End If


If a pattern match is successful, the Value property contains the matched substring, the Index property indicates the zero-based starting position of the matched substring in the input string, and the Length property indicates the length of matched substring in the input string.

Because a single match can involve multiple capturing groups, Match has a Groups property that returns the GroupCollection. The GroupCollection has accessors that return each group. The Match instance itself is equivalent to the first object in the collection, at Match.Groups[0] (Match.Groups(0) in Visual Basic), which represents the entire match.

The following examples use the regular expression Console\.Write(Line)?. The regular expression is interpreted as follows:

Console\.Write

Match the string "Console.Write". Note that the "." character is escaped so that it is interpreted as a literal period rather than as a wildcard that matches any character.

(Line)?

Match zero or one occurrence of the string "Line".

Example 1

The following example calls the Regex.Matches(String, String) method to retrieve all pattern matches in an input string. It then iterates the Match objects in the returned MatchCollection object to display information about each match.


Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim input As String = "Dim values() As Integer = { 1, 2, 3 }" & vbCrLf & _
                            "For ctr As Integer = values.GetLowerBound(1) To values.GetUpperBound(1)" & vbCrLf & _
                            "   Console.Write(values(ctr))" & vbCrLf & _
                            "   If ctr < values.GetUpperBound(1) Then Console.Write("", "")" & vbCrLf & _
                            "Next" & vbCrLf & _
                            "Console.WriteLine()"   
      Dim pattern As String = "Console\.Write(Line)?"
      Dim matches As MatchCollection = Regex.Matches(input, pattern)
      For Each match As Match In matches
         Console.WriteLine("'{0}' found in the source code at position {1}.", _ 
                           match.Value, match.Index)       
      Next                            
   End Sub
End Module
' The example displays the following output:
'    'Console.Write' found in the source code at position 115.
'    'Console.Write' found in the source code at position 184.
'    'Console.WriteLine' found in the source code at position 211.


Example 2

The following example calls the Match(String, String) and NextMatch methods to retrieve one match at a time.


Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim input As String = "Dim values() As Integer = { 1, 2, 3 }" & vbCrLf & _
                            "For ctr As Integer = values.GetLowerBound(1) To values.GetUpperBound(1)" & vbCrLf & _
                            "   Console.Write(values(ctr))" & vbCrLf & _
                            "   If ctr < values.GetUpperBound(1) Then Console.Write("", "")" & vbCrLf & _
                            "Next" & vbCrLf & _
                            "Console.WriteLine()"   
      Dim pattern As String = "Console\.Write(Line)?"
      Dim match As Match = Regex.Match(input, pattern)
      Do While match.Success
         Console.WriteLine("'{0}' found in the source code at position {1}.", _ 
                           match.Value, match.Index)
         match = match.NextMatch()                  
      Loop                            
   End Sub
End Module
' The example displays the following output:
'    'Console.Write' found in the source code at position 115.
'    'Console.Write' found in the source code at position 184.
'    'Console.WriteLine' found in the source code at position 211.


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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