Define a regular expression for repeated words

 

Imports System
Imports System.Text.RegularExpressions

Public Module Test

    Public Sub Main()

        Dim rx As New Regex("\b(?<word>\w+)\s+(\k<word>)\b",RegexOptions.Compiled Or RegexOptions.IgnoreCase)
        Dim text As String = "this is is a test test."

        Dim matches As MatchCollection = rx.Matches(text)

        Console.WriteLine("{0} matches found in:", matches.Count)

        For Each match As Match In matches
            Dim groups As GroupCollection = match.Groups
            Console.WriteLine("'{0}' repeated at positions {1} and {2}", _
                              groups.Item("word").Value, _
                              groups.Item(0).Index, _
                              groups.Item(1).Index)
        Next
    End Sub
End Module

Related examples in the same category

1.	Use Regular Expression to Validate Email address
2.	Validate TextBox: cannot be empty
3.	TextBox validation: validate in KeyPressed Event
4.	Use Regular Expressions to parse IP address
5.	Use Regex to separate strings
6.	Use Regx.split to split string
7.	Use Regex to match
8.	Regular to parse time: 04:03:27
9.	Regular Expressions Match
10.	Use Regular Expressions to Split String
11.	Demonstrating Class Regex
12.	Regular Expressions: Validate Name
13.	Regular Expressions: Validate Address
14.	Regular Expressions: Validate City
15.	Regular Expressions: Validate Zip Code
16.	Regular Expressions: validate Phone Number
17.	Using Regex method Replace: ^
18.	Using Regex method Replace: by another string
19.	Using Regex method Replace:\w+	$Using Regex method Replace:\w+$
20.	Using Regex method Replace:First 3 digits replaced
21.	Using Regex method Replace: String split at commas
22.	Strip tags from HTML to create Text version of a web page
23.	\w matches any word character.
24.	(\w) matches a word character. This is the first capturing group.
25.	\1 match the value of the first capture.
26.	\s matches any white-space character.
27.	\b: Begin the match at a word boundary.
28.	\w+: Match one or more word characters.
29.	(e)*: Match an "e" either zero or one time.
30.	(\s\|$) Match either a whitespace character or the end of the input string.
31.	^: Begin the match at the beginning of the input string.
32.	\D: Match a non-digit character.
33.	\d{1,5} Matches from one to five decimal digits.
34.	\D* matches zero or one non-decimal character.
35.	$ Matches the end of the input string.
36.	\S matches any non-white-space character.
37.	\b: Begin the match at a word boundary.
38.	(\S+): matches one or more non-white-space characters. This is the first capturing group.
39.	\s*: matches zero or one white-space character.
40.	Regular expression for class and group
41.	Decimal Digit Character: \d
42.	Parse Link and Image tags in a HTML file
43.	Parse Image tags in a HTML file
44.	Regex Class represents an immutable regular expression.
45.	Find duplicates
46.	ArgumentException Class is thrown when one of the arguments provided to a method is not valid.
47.	ArgumentOutOfRangeException is thrown when the value of an argument is outside the allowable range
48.	Capture Class represents the results from a single successful subexpression capture.
49.	CharUnicodeInfo Class has information about a Unicode character
50.	Validate email address
51.	Regex.Split

Define a regular expression for repeated words : Regular Expressions « Development « VB.Net

Related examples in the same category