Regex.Matches Method (String, String, RegexOptions)

The Matches(String, String, RegexOptions) method is similar to the Match(String, String, RegexOptions) method, except that it returns information about all the matches found in the input string, instead of a single match. It is equivalent to the following code:

Match match = Regex.Match(input, pattern, options);
while (match.Success) {
      // Handle match here...

      match = match.NextMatch();
}  

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 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 members of this collection such 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.

Because of its lazy evaluation, calling the Matches(String, String) method does not throw a RegexMatchTimeoutException exception. However, the exception is thrown when an operation is performed on the MatchCollection object returned by this method, if a time-out interval is defined by the "REGEX_DEFAULT_MATCH_TIMEOUT" property of the current application domain and a matching operation exceeds this time-out interval.

This method times out after an interval that is equal to the default time-out value of the application domain in which it is called. If a time-out value has not been defined for the application domain, the value Regex.InfiniteMatchTimeout, which prevents the method from timing out, is used. The recommended static method for retrieving multiple pattern matches is Regex.Matches(String, String, RegexOptions, TimeSpan), which lets you set the time-out interval.

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) method to perform a case-insensitive comparison of the pattern with the input string. As the output shows, the two methods return different results.

using System;
using System.Text.RegularExpressions;

public class Example
{
   public static void Main()
   {
      string pattern = @"\b\w+es\b";
      string sentence = "NOTES: Any notes or comments are optional.";

      // Call Matches method without specifying any options. 
      foreach (Match match in Regex.Matches(sentence, pattern))
         Console.WriteLine("Found '{0}' at position {1}", 
                           match.Value, match.Index);
      Console.WriteLine();

      // Call Matches method for case-insensitive matching. 
      foreach (Match match in Regex.Matches(sentence, pattern, RegexOptions.IgnoreCase))
         Console.WriteLine("Found '{0}' at position {1}", 
                           match.Value, match.Index);
   }
}
// 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.

.NET Framework

.NET Framework Client Profile

Portable Class Library

.NET for Windows Store apps

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

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