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Group.Captures Property

Gets 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.

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

'Declaration
Public ReadOnly Property Captures As CaptureCollection

Property Value

Type: System.Text.RegularExpressions.CaptureCollection
The collection of substrings matched by the group.

If a quantifier is not applied to a capturing group, the collection returned by the Captures property contains a single Capture object that provides information about the same substring as the Group object. This is illustrated in the following example. It defines a regular expression, \b(\w+)\b, that extracts a single word from a sentence. The Group object captures the word "This", and the single object in the CaptureCollection contains information about the same capture.


Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim pattern As String = "\b(\w+)\b"
      Dim input As String = "This is one sentence."
      Dim match As Match = Regex.Match(input, pattern)
      If match.Success Then
         Console.WriteLine("Matched text: {0}", match.Value)
         For ctr As Integer = 1 To match.Groups.Count - 1
            Console.WriteLine("   Group {0}:  {1}", ctr, match.Groups(ctr).Value)
            Dim captureCtr As Integer = 0
            For Each capture As Capture In match.Groups(ctr).Captures
               Console.WriteLine("      Capture {0}: {1}", _
                                 captureCtr, capture.Value)
               captureCtr += 1                  
            Next
         Next
      End If   
   End Sub
End Module
' The example displays the following output:
'       Matched text: This
'          Group 1:  This
'             Capture 0: This


The real utility of the Captures property occurs when a quantifier is applied to a capturing group so that the group captures multiple substrings in a single regular expression. In this case, the Group object contains information about the last captured substring, whereas the Captures property contains information about all the substrings captured by the group. In the following example, the regular expression \b(\w+\s*)+\. matches an entire sentence that ends in a period. The group (\w+\s*)+ captures the individual words in the collection. Because the Group collection contains information only about the last captured substring, it captures the last word in the sentence, "sentence". However, each word captured by the group is available from the collection returned by the Captures property.


Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim input As String = "This is a sentence. This is another sentence."
      Dim pattern As String = "\b(\w+\s*)+\."
      Dim match As Match = Regex.Match(input, pattern)
      If match.Success Then
         Console.WriteLine("Matched text: {0}", match.Value)
         For ctr As Integer = 1 To match.Groups.Count - 1
            Console.WriteLine("   Group {0}:  {1}", ctr, match.Groups(ctr).Value)
            Dim captureCtr As Integer = 0
            For Each capture As Capture In match.Groups(ctr).Captures
               Console.WriteLine("      Capture {0}: {1}", _
                                 captureCtr, capture.Value)
               captureCtr += 1                  
            Next
         Next
      End If   
   End Sub
End Module
' The example displays the following output:
'       Matched text: This is a sentence.
'          Group 1:  sentence
'             Capture 0: This
'             Capture 1: is
'             Capture 2: a
'             Capture 3: sentence


.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.

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