Regex.Matches Method (String, String, RegexOptions)
Updated: September 2010
Searches the specified input string for all occurrences of a specified regular expression, using the specified matching options.
Assembly: System (in System.dll)
'Declaration Public Shared Function Matches ( _ input As String, _ pattern As String, _ options As RegexOptions _ ) As MatchCollection 'Usage Dim input As String Dim pattern As String Dim options As RegexOptions Dim returnValue As MatchCollection returnValue = Regex.Matches(input, _ pattern, options)
Parameters
- input
- Type: System.String
The string to search for a match.
- pattern
- Type: System.String
The regular expression pattern to match.
- options
- Type: System.Text.RegularExpressions.RegexOptions
A bitwise combination of the enumeration values that specify options for matching.
Return Value
Type: System.Text.RegularExpressions.MatchCollectionA collection of the Match objects found by the search. If no matches are found, the method returns an empty collection object.
| Exception | Condition |
|---|---|
| ArgumentException | A regular expression parsing error has occurred. |
| ArgumentNullException | input is Nothing. -or- pattern is Nothing. |
| ArgumentOutOfRangeException | options is not a valid bitwise combination of RegexOptions values. |
The Matches method is similar to the Match method, except that it returns information about all the matches, instead of a single match, found in the input string. It is equivalent to the following code:
The collection includes only successful matches and terminates at the first unsuccessful match.
The static Matches methods are equivalent to constructing a Regex object with the specified regular expression pattern and calling the instance method Matches.
The pattern parameter consists of various 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.
The Matches method uses lazy evaluation to populate the returned MatchCollection object. Accessing such members of this collection as MatchCollection.Count and MatchCollection.CopyTo causes the collection to be populated immediately. To take advantage of lazy evaluation, you should iterate the collection by using a construct such as foreach in C# and For Each…Next in Visual Basic.
The following example calls the Matches(String, String) method to identify any word in a sentence that ends in "es", and then calls the Matches(String, String, RegexOptions) to perform a case-insensitive comparison of the pattern with the input string. As the output shows, the two methods return different results.
Imports System.Text.RegularExpressions Module Example Public Sub Main() Dim pattern As String = "\b\w+es\b" Dim sentence As String = "NOTES: Any notes or comments are optional." ' Call Matches method without specifying any options. For Each match As Match In Regex.Matches(sentence, pattern) Console.WriteLine("Found '{0}' at position {1}", match.Value, match.Index) Next Console.WriteLine() ' Call Matches method for case-insensitive matching. For Each match As Match In Regex.Matches(sentence, pattern, RegexOptions.IgnoreCase) Console.WriteLine("Found '{0}' at position {1}", match.Value, match.Index) Next End Sub End Module ' The example displays the following output: ' Found 'notes' at position 11 ' ' Found 'NOTES' at position 0 ' Found 'notes' at position 11
The regular expression pattern \b\w+es\b is defined as shown in the following table.
Pattern | Description |
|---|---|
\b | Begin the match at a word boundary. |
\w+ | Match one or more word characters. |
es | Match the literal string "es". |
\b | End the match at a word boundary. |
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The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.