[RESOLVED] RegEx questions!

[dinosaur_uk]

Hi all,

I am a RegEx virgin and have no idea where to start. I have three questions which i would be more than gratefull if you could help me.

1. Where is the best place to start learning RegEx?
2. If i have an array list full of text, how can i search for a string which is in the list?

For example, if i enter the search string "bob test" in this text:
Hi there, this is bob giving a testing

it will return a true. However, if there is only one match, it will also return a true.

3. thirdly, how can i search and pick out the link which is surrounded with the following tags? <link>http://etc etc te</link>

CHeers,

Ken

[danasegarane]

RegExLib.com is the best place to start and for implementing with .net you could visit MSDN

[.paul.]

I can answer 1 of your questions

1/ Try this

[stanav]

1. I use this free tool to learn/test regex patterns
http://www.ultrapico.com/Expresso.htm

2. Use a List(Of String) is a better choice than the old arraylist class. You can then call one of its find methods (Find, FindAll, FindIndex, FindLast....). MSDN even has an example on this.

3. Using regex.

[dinosaur_uk]

Ok,

I've found that I can use the following regex to pick up the link, but how do i capture the text?

(<link>) will capture the first one, but how do i know when it is ending?

<[^<]+?> will capture all tags between which has < > enclosing it.

Could you please help me? I dont know how to capture the link enclosed between <link></link>

cheers

[stanav]

Try this pattern

Dim pattern as string = "(?<=\<link\>).+(?=\</link\>)"

[dinosaur_uk]

' Regex match
Dim options As RegexOptions = RegexOptions.None
Dim regex As System.Text.RegularExpressions.Regex = New System.Text.RegularExpressions.Regex("<link\b[^>]*>(.*?)</link>")
Dim input As String = Me.TextBox1.Text

' Get matches
Dim matches As MatchCollection = regex.Matches(input)
Dim i As Integer
For i = 0 To matches.Count - 1
' TODO: Do something with result
System.Windows.Forms.MessageBox.Show(matches(i).Groups(1).Value, "Match")
Next i

[dinosaur_uk]

' Regex match
        Dim options As RegexOptions = RegexOptions.None
        Dim regex As System.Text.RegularExpressions.Regex = New System.Text.RegularExpressions.Regex("<link\b[^>]*>(.*?)</link>")
        Dim input As String = Me.TextBox1.Text
 
        ' Get matches
        Dim matches As MatchCollection = regex.Matches(input)
        Dim i As Integer
        For i = 0 To matches.Count - 1
            ' TODO: Do something with result
            System.Windows.Forms.MessageBox.Show(matches(i).Groups(1).Value, "Match")
        Next i