MatchCollection Class

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Represents the set of successful matches found by iteratively applying a regular expression pattern to the input string.


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

<SerializableAttribute> _
Public Class MatchCollection _
	Implements ICollection, IEnumerable

The MatchCollection type exposes the following members.

Public propertyCountGets the number of matches.
Public propertyIsReadOnlyGets a value that indicates whether the collection is read only.
Public propertyIsSynchronizedGets a value indicating whether access to the collection is synchronized (thread-safe).
Public propertyItemGets an individual member of the collection.
Public propertySyncRootGets an object that can be used to synchronize access to the collection.

Public methodCopyToCopies all the elements of the collection to the given array starting at the given index.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetEnumeratorProvides an enumerator that iterates through the collection.
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

The collection is immutable (read-only) and has no public constructor. The Regex..::..Matches method returns a MatchCollection object.

The collection contains zero or more System.Text.RegularExpressions..::..Match objects. If the match is successful, the collection is populated with one System.Text.RegularExpressions..::..Match object for each match found in the input string. If the match is unsuccessful, the collection contains no System.Text.RegularExpressions..::..Match objects, and its Count property equals zero.

When applying a regular expression pattern to a particular input string, the regular expression engine uses either of two techniques to build the MatchCollection object:

  • Direct evaluation.

    The MatchCollection object is populated all at once, with all matches resulting from a particular call to the Regex..::..Matches method. This technique is used when the collection's Count property is accessed. It typically is the more expensive method of populating the collection and entails a greater performance hit.

  • Lazy evaluation.

    The MatchCollection object is populated as needed on a match-by-match basis. It is equivalent to the regular expression engine calling the Regex..::..Match method repeatedly and adding each match to the collection. This technique is used when the collection is accessed through its GetEnumerator method, or when it is accessed using the foreach statement (in C#) or the For Each...Next statement (in Visual Basic).

To iterate through the members of the collection, you should use the collection iteration construct provided by your language (such as foreach in C# and For EachNext in Visual Basic) instead of retrieving the enumerator that is returned by the GetEnumerator method.

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