Regex...:. IsMatch method (String, String, RegexOptions)

Source: Internet
Author: User
Tags expression engine
IsMatch method (String, String, RegexOptions)

. NET Framework class library for Silverlight Regex...:. IsMatch method (String, String, RegexOptions)

Indicates the regular expression usage.PatternThe Regular Expression andOptionsWhether the matching option provided by the parameter is found in the input string.

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

Syntax

Visual Basic (Declaration)
Public Shared Function IsMatch ( _    input As String, _    pattern As String, _    options As RegexOptions _) As Boolean

Visual Basic (usage)
Dim input As StringDim pattern As StringDim options As RegexOptionsDim returnValue As BooleanreturnValue = Regex.IsMatch(input, _    pattern, options)

C #
public static bool IsMatch(    string input,    string pattern,    RegexOptions options)

Parameters
Input
Type: System...:. String
The string to search for matching items.
Pattern
Type: System...:. String
The regular expression pattern to be matched.
Options
Type: System. Text. RegularExpressions...:. RegexOptions
The bitwise combination of enumerated values.
Return Value

Type: System...:. Boolean
True if the regular expression finds a match. Otherwise, false.

Exception

Exception Condition
ArgumentException

Regular Expression Analysis Error.

ArgumentNullException

InputIs a nullNothingnullptrnull reference (Nothing in Visual Basic ).

-Or-

PatternIs a nullNothingnullptrnull reference (Nothing in Visual Basic ).

ArgumentOutOfRangeException

OptionsIt is not a valid RegexOptions value.

Remarks

The IsMatch method is usually used to verify a string, or ensure that the string conforms to the specified mode for subsequent operations without retrieving the string. To determine whether one or more strings Match a regular expression pattern and retrieve these strings for subsequent operations, call the Match or Matches method.

StaticIsMatch (String, String, RegexOptions)The method is equivalentPatternThe specified regular expression mode andOptionsThe specified Regular Expression option constructs the Regex object and calls the IsMatch (String) instance method. This regular expression mode will be cached for quick retrieval by the Regular Expression Engine.

PatternA parameter is composed of various regular expression language elements that describe the string to be matched by a symbol. For more information about regular expressions, see. NET Framework regular expressions in the. NET Framework documentation and the theme of the Regular Expression Language element.

Example

The following example illustrates how to use the IsMatch (String, String) method to determine whether a String is a valid part number. This regular expression assumes that this part number has a specific format (consisting of three groups of characters separated by a hyphen ). The first group contains four characters, which must be a letter or digit followed by two digits followed by a letter or digit. The second group consists of three characters and must be a number. The third group consists of four characters, which must contain three digits followed by one letter or digit.

Visual Basic

Copy code

Imports System.Text.RegularExpressionsModule Example   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)      Dim partNumbers() As String = {"1298-673-4192", "A08Z-931-468a", _                                      "_A90-123-129X", "12345-KKA-1230", _                                      "0919-2893-1256"}      Dim pattern As String = "^[A-Z0-9]\d{2}[A-Z0-9](-\d{3}){2}[A-Z0-9]$"      For Each partNumber As String In partNumbers         outputBlock.Text += String.Format("{0} {1} a valid part number.", _                           partNumber, _                           IIf(Regex.IsMatch(partNumber, pattern, RegexOptions.IgnoreCase), _                               "is", "is not")) & vbCrLf      Next   End SubEnd Module' The example displays the following output:'       1298-673-4192 is a valid part number.'       A08Z-931-468a is a valid part number.'       _A90-123-129X is not a valid part number.'       12345-KKA-1230 is not a valid part number.'       0919-2893-1256 is not a valid part number.

C #

Copy code

using System;using System.Text.RegularExpressions;public class Example{   public static void Demo(System.Windows.Controls.TextBlock outputBlock)   {      string[] partNumbers = { "1298-673-4192", "A08Z-931-468a",                               "_A90-123-129X", "12345-KKA-1230",                               "0919-2893-1256" };      string pattern = @"^[A-Z0-9]\d{2}[A-Z0-9](-\d{3}){2}[A-Z0-9]$";      foreach (string partNumber in partNumbers)         outputBlock.Text += String.Format("{0} {1} a valid part number.",                           partNumber,                           Regex.IsMatch(partNumber, pattern, RegexOptions.IgnoreCase)                                         ? "is" : "is not") + "\n";   }}// The example displays the following output://       1298-673-4192 is a valid part number.//       A08Z-931-468a is a valid part number.//       _A90-123-129X is not a valid part number.//       12345-KKA-1230 is not a valid part number.//       0919-2893-1256 is not a valid part number.

The regular expression mode is:

Copy code

^[A-Z0-9]\d{2}[A-Z0-9](-\d{3}){2}[A-Z0-9]$

The following table shows how to explain the regular expression mode.

Mode

Description

^

Starts from the beginning of the string.

A-Z0-9

Match any single letter character (A to Z) or any number character.

\ D {2}

Match two numeric characters.

A-Z0-9

Match any single letter character (A to Z) or any number character.

-

Match a hyphen.

\ D {3}

Matches exactly three numeric characters.

(-\ D {3}) {2}

Search for the mode in which a single character is followed by three numeric characters and match two matching items in this mode.

A-Z0-9

Match any single letter character (A to Z) or any number character.

$

End the match at the end of the string.

InOptionsWhen the parameter is set to RegexOptions...:. IgnoreCaseIsMatch (String, String, RegexOptions)The method is equivalent to defining the following regular expressions:

Copy code

[a-zA-Z0-9]\d{2}[a-zA-Z0-9](-\d{3}){2}[A-Za-z0-9]

For comparison, see the IsMatch (String, String) method example.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.