This class represents a regular
expression. Use
it to search for patterns in string data. It provides static methods
that search for a pattern without explicitly creating
Regex instances as well as instance methods that
allow you to interact with a Regex object.
The various static methods employed by Regex take
the input string to search for as the first argument and the regular
expression pattern string as the second. This is equivalent to
constructing a Regex instance with a pattern
string, using it, and destroying it immediately. Most methods are
overloaded as instance methods as well. These do not require a
pattern argument, as this is provided with the constructor.
The Match( ) and Matches( )
methods search an input string for a single match or all matches.
Their overloads are the same. The first argument is the input string.
You can specify which position in the string the search should start
at using a second integer parameter. Match( ) also
lets you specify the length of substring to search after that
position. IsMatch( ) works the same way as
Match( ), except that it returns a boolean
indicating whether the string contains a match.
The Split( ) method acts like the
System.String.Split( ) method. It uses the
Regex pattern as a delimiter to split the input
string into an array of substrings. (The delimiter is not included in
the substrings.) You can provide a maximum number of substrings to
return, in which case the last substring returned is the remainder of
the input string. You can also specify the position to start in the
input string and a RegexOptions parameter.
The Replace( ) method uses a replacement string to
replace each pattern match in an input string. The replacement string
can include regular characters and backreference variable constructs
(e.g., $1 or ${name}).
Replace( ) can iterate through every match found
in the input string, or it can specify a maximum number of
replacements to perform. Replace( ) can also take
an argument specifying a MatchEvaluator delegate,
which is called every time a match is found.
Two additional static methods can transform strings used with regular
expressions. Escape( ) converts a string
containing regular expression metacharacters by replacing them with
escaped equivalents (for example, ? would be
changed to \?). The set of metacharacters
converted is \, *,
+, ?, |,
{, [, (,
), ^, $,
., #, and any whitespace. The
Unescape( ) method replaces escaped characters
within a string with their unescaped equivalents. Use
Escape( ) and Unescape( ) when
you need to use one of these metacharacters as a literal in a regular
expression.
A set of instance methods for Regex provides
information on the capturing groups contained in the expression.
GetGroupNames( ) and GetGroupNumbers(
) each return an array containing the names of all the
capture groups or numbers of all capture groups, respectively. The
GroupNameFromNumber( ) and
GroupNumberFromName( ) methods return the
corresponding name or number from the argument given to them.
CompileToAssembly( ) allows you to create your own
type for a regular expression object and save it to disk as an
assembly. This is a static method that takes a
RegexCompilationInfo object and assembly
information to build the type. The
RegexCompilationInfo object contains the regular
expression pattern and additional information needed for the
compilation.
public class Regex : System.Runtime.Serialization.ISerializable {
// Public Constructors
public Regex(string pattern);
public Regex(string pattern, RegexOptions options);
// Protected Constructors
protected Regex( );
// Public Instance Properties
public RegexOptions Options{get; }
public bool RightToLeft{get; }
// Public Static Methods
public static void CompileToAssembly(RegexCompilationInfo[ ] regexinfos,
System.Reflection.AssemblyName assemblyname);
public static void CompileToAssembly(RegexCompilationInfo[ ] regexinfos,
System.Reflection.AssemblyName assemblyname,
System.Reflection.Emit.CustomAttributeBuilder[ ] attributes);
public static void CompileToAssembly(RegexCompilationInfo[ ] regexinfos,
System.Reflection.AssemblyName assemblyname,
System.Reflection.Emit.CustomAttributeBuilder[ ] attributes, string resourceFile);
public static string Escape(string str);
public static bool IsMatch(string input, string pattern);
public static bool IsMatch(string input, string pattern, RegexOptions options);
public static Match Match(string input, string pattern);
public static Match Match(string input, string pattern, RegexOptions options);
public static MatchCollection Matches(string input, string pattern);
public static MatchCollection Matches(string input, string pattern, RegexOptions options);
public static string Replace(string input, string pattern, MatchEvaluator evaluator);
public static string Replace(string input, string pattern, MatchEvaluator evaluator,
RegexOptions options);
public static string Replace(string input, string pattern, string replacement);
public static string Replace(string input, string pattern, string replacement,
RegexOptions options);
public static string[ ] Split(string input, string pattern);
public static string[ ] Split(string input, string pattern, RegexOptions options);
public static string Unescape(string str);
// Public Instance Methods
public string[ ] GetGroupNames( );
public int[ ] GetGroupNumbers( );
public string GroupNameFromNumber(int i);
public int GroupNumberFromName(string name);
public bool IsMatch(string input);
public bool IsMatch(string input, int startat);
public Match Match(string input);
public Match Match(string input, int startat);
public Match Match(string input, int beginning, int length);
public MatchCollection Matches(string input);
public MatchCollection Matches(string input, int startat);
public string Replace(string input, MatchEvaluator evaluator);
public string Replace(string input, MatchEvaluator evaluator, int count);
public string Replace(string input, MatchEvaluator evaluator, int count, int startat);
public string Replace(string input, string replacement);
public string Replace(string input, string replacement, int count);
public string Replace(string input, string replacement, int count, int startat);
public string[ ] Split(string input);
public string[ ] Split(string input, int count);
public string[ ] Split(string input, int count, int startat);
public override string ToString( );
// overrides object
// Protected Instance Methods
protected override void Finalize( );
// overrides object
protected void InitializeReferences( );
protected bool UseOptionC( );
protected bool UseOptionR( );
}
