Thom Robbins: Regular Expressions

Code Camp II: The Return!

Thu, 22 Jul 2004 15:20:34 GMT

*********CALL FOR SPEAKERS*********

Developer Code Camp II: The Return!

October 16/17, 2004

October 16 – 8:30 AM – 9PM

October 17 – 8:30 AM – 4PM

Microsoft Waltham

Schedule: http://radio.weblogs.com/0131777/CodeCamp2/code2.htm

General Call for Speakers

Code Camp II is looking for speakers and session leaders.

Code Camp II: The Return is looking to be even bigger and better than anything we have done before. The secret is you! This is a New England developer community based event that requires both speakers and attendees. The continuing goal of the Code Camps series is to provide an intensive developer to developer learning experience that is fun and technically stimulating. The primary focus is on delivering programming information and sample code that can be used immediately. The event is free and all slides, manuals and demo code are provided free!

This two day camp is hosted in our Waltham facility. As a community based event this is a general call for speakers and session leaders to help make this event a success. Based on your feedback, Code Camp II will now feature two types of 1.5 hour sessions and three defined tracks

Do you have something to say?

Requested Session Types:

Code focused presentation – These are presentations that include both power points and code demos. Given the audience that is attending it is important that a large amount of the presentation is focused on code and coding related techniques. Sample topics include How To and Best Practice Sessions.

Chalk Talks – These are new to the Code Camp. These sessions are designed as a facilitated discussion around a specific topic. No pre-canned demos, or pre-prepared code samples allowed! They are presented as a free form facilitated discussion that leverages the expertise of the presenter and the combined knowledge of the group to explore a specific topic.

Additionally, based on feedback we are sponsoring the following three tracks. All presentations must fall into these tracks to be considered. One of the strongest pieces of feedback from the last Code Camp was to provide a better organized set of tracks:

Code Camp Tracks:

Smart Client – This track is designed for presentations or chalk talks on topics related to Smart Client related development topics. This includes Windows Forms applications, Microsoft Office or mobile devices.

Web Track – This track is designed for presentations or chalk talks about Web based development that includes ASP.NET and Web Services.

Data Track – This track is designed for presentation and chalk talks about data storage technologies that includes SQL Server and XML.

********Submit Your Sessions********

Please complete the following and return it to trobbins@microsoft.com by September 15.

Once your session abstract is received we will review and provide scheduling for the selected sessions by October 1. All slides and code samples for the presentation must be delivered by October 14. If we are unable to fill all the time slots for the two days, the code camp will be shortened. It is the community that makes this event a success!

Name:
Company:
Email:
Phone:
Session Type:	Chalk Talk/Presentation (Select one)
Track:	Web/Smart Client/Data (Select one)
Level	200/300/400
Session Name:
Session Description:

ADO.NET Best Practices

Sat, 05 Jun 2004 20:31:47 GMT

I really love talking to the local New England User Groups. I always have a great time and always manage to learn a few things myself. I think the information sharing at these groups really make it a worthwhile time investment. As I promised here are the slides and code samples for my talk on ADO.NET Best Practices.

Validating Email Addresses

Sat, 27 Mar 2004 23:31:51 GMT

While doing some coding the other day I needed an expression to validate email addresses. The trick was that it had to be flexible enough to handle emails in the format of username@company.com and firstname.lastname@company.com.

Imports System.Text.RegularExpressions

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim strEmail As String = "thom.robbins@microsoft.com"

Dim regexp As New Regex("^([\w-]+\.)*?[\w-]+@[\w-]+\.([\w-]+\.)*?[\w]+$")

If regexp.IsMatch(strEmail) Then

MsgBox("Valid Email")

Else

MsgBox("Invalid Email")

End If

End Sub

Character Matching Using the Period

Sun, 25 Jan 2004 22:22:11 GMT

Character matching is one of the most powerful features of regular expressions. They allow the developer to quickly find certain patterns and characters within strings. The “.” is one of the most important and easiest to use examples of this. The period is a special character with regular expressions that allows the search to find any single character that can exist (except new lines) within an expression. For example, using the following code we can find the value “brown” out of the string.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim strExpression As String = "The quick brown fox jumped over

the small fence"

Dim regexp As New Regex("b.own")

If regexp.IsMatch(strExpression) Then

‘ return brown

MsgBox("Expression found")

Else

‘ remove brown and you will get this

MsgBox("Expression not found")

End If

End Sub

Phone Number Validation

Sun, 25 Jan 2004 03:03:03 GMT

Simple example of validating a phone number:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
      ' Invalid phone number
     'Dim strPhone As String = "123456789"

    ' valid phone number
    Dim strPhone As String = "(123) 456-7890"
    Dim regexp As New Regex(("^$?\d{3}$?\s|-\d{3}-\d{4}$"))

     If regexp.IsMatch(strPhone) Then
           MsgBox("Valid Phone Number")
    Else
          MsgBox("Invalid Phone Number")
   End If

End Sub

Zip Code Validation

Sun, 25 Jan 2004 02:53:15 GMT

I was recently putting together some proof of concept for a customer and realized that I hadn't posted one of the common Regular Expressions that I had been using.

Validating a Zip Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' Invalid Zip code
        'Dim strZip As String = "AB123"

        ' valid Zip Code
       Dim strZip As String = "03110"

      Dim regexp As New Regex(("^\d{5}$"))

      If regexp.IsMatch(strZip) Then
                   MsgBox("Zip Code")
     Else
                  MsgBox("No zip match")
     End If

End Sub

Regular Expressions Cheat Sheet

Sun, 25 Jan 2004 02:26:02 GMT

Found an excellent cheat sheet for Regular Expressions. Well worth checking out.

http://www.regexlib.com/CheatSheet.htm

Formatting a Proper Name

Tue, 20 Jan 2004 01:35:33 GMT

Regular expressions are about finding and changing patterns. One of the most common that I always find is the need to reformat a “proper name”. It seems that every conversion program that I get involved in requires the re-ordering of the name. Regular expressions offer something called a backreference that can help with this. Basically, these patterns sets allow a quick way of finding the same string pattern again.

For an example, let’s assume that we have an inbound text string that has my name as “Robbins, Thom”. Unfortunately, when this string is updated it needs to be in the proper name format of “Thom Robbins”. Using a regular expression with a backreference, the following code can be used to switch these values.

Imports System.Text.RegularExpressions

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim importname As String = "Robbins, Thom"

Dim regexp As New Regex("(\w+),\s(\w+)")

Dim updatename = regexp.Replace(importname, "$2 $1")

MsgBox(updatename)

End Sub

The above example matches two words separated by a comma and a space then reverses the order of the words. The Replace statement uses the $N notation to reference the Nth group of parenthesis.

Note: When you want to refer to the entire text string use the $0

Regular Expressions Example

Mon, 19 Jan 2004 02:07:12 GMT

At some point everyone has written code to test values that match patterns. There are many different ways this can be done. Typical examples, include string handling or using the myriad of other algorithms available. Recently, I have been working the Regular Expressions available within .NET. I am pretty impressed with their simplicity and power. The downside is that many times they can be quite the mental puzzle to figure out. I can easily understand how these can be overwhelming to understand and use. Over the next couple of weeks, I am planning on blogging about some of these that I have been playing with and collecting.

Here is a simple example that checks to see if a string contains a specific phrase:

Imports System.Text.RegularExpressions

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim r As Regex = New Regex("(\w+)\s+(blue)")

Dim comstring As String = "blue ball"

If r.IsMatch(comstring) Then

MsgBox("Match Successful")

Else

MsgBox("Match failed")

End If

End Sub

Keep an eye out for additional ones that I will post. If you have any examples that you want to add – email me with any samples you may have and want posted.