Regular Expression Examples

This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Developer's Guide

Updated: November 2007

This section contains code examples that illustrate the use of regular expressions in common applications.

Note:
The System.Web.RegularExpressions namespace contains a number of regular expression objects that implement predefined regular expression patterns for parsing strings from HTML, XML, and ASP.NET documents. For example, the TagRegex class identifies start tags in a string and the CommentRegex class identifies ASP.NET comments in a string.

In This Section

Example: Scanning for HREFS: Provides an example that searches an input string and prints out all the href="…" values and their locations in the string.
Example: Changing Date Formats: Provides an example that replaces dates in the form mm/dd/yy with dates in the form dd-mm-yy.
How to: Extract a Protocol and Port Number from a URL: Provides an example that extracts a protocol and port number from a string that contains a URL. For example, "http://www.contoso.com:8080/letters/readme.html" returns "http:8080".
How to: Strip Invalid Characters from a String: Provides an example that strips invalid non-alphanumeric characters from a string.
How to: Verify that a String is in Valid E-Mail Format: Provides an example that you can use to verify that a string is in valid e-mail format.

Reference

System.Text.RegularExpressions: Provides class library reference information for the .NET Framework System.Text.RegularExpressions namespace.

Related Sections

Regular Expressions as a Language: Provides an overview of the programming language aspect of regular expressions.
Regular Expression Classes: Describes the regular expression classes contained in the System.Text.RegularExpression namespace and provides examples of their use.
Details of Regular Expression Behavior: Provides information about the capabilities and behavior of .NET Framework regular expressions.
Regular Expression Language Elements: Provides information on the set of characters, operators, and constructs that you can use to define regular expressions.