How to get the string and added into a list? - regex

Question

The files that are going to load is xml file. after I get to the specific path, which is I wanted to get the specific string by lines, then added it into a list.
These are the example of strings that I want to extract from a file. (highlighted from a bold text.
<XMLTAG>
<p><b>[1]</b> Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum <LINK HREF="test"><i>NAME</i> [2017] 3 ABCD 247</LINK> [1234] 1 ABC 123; [1234] 1 ABC 123:</p>
<p><b>[2]</b> <LINK HREF="test"><i>NAME</i> [2017] 3 ABCD 247</LINK> [1234] 1 ABC 123 lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.</p>
</XMLTAG>
I wanted to extract [1234] 1 ABC 123; [1234] 1 ABC 123 and insert it in the same line as first in the list.
These are the codes for extraction.
Private Function Slist(ByVal list As List(Of String)) As List(Of String)
Dim rlist As List(Of String) = New List(Of String)
Dim temp As String = ""
For i As Integer = 0 To list.Count - 1 Step 1
If i = 0 Then
temp = list(i).ToString
ElseIf i = list.Count - 1 Then ' 2nd & before last
If list(i).ToString.Contains("<i>") Then
rlist.Add(temp )
temp = list(i).ToString
rlist.Add(temp)
Else
temp = temp & "; " & list(i).ToString
rlist.Add(temp)
End If
Else 'first
If list(i).ToString.Contains("<i>") Then
rlist.Add(temp)
temp = list(i).ToString
Else
temp = temp & "; " & list(i).ToString
End If
End If
Next
Return rlist.Distinct.ToList
End Function
I don't know another options on how to extract string after , I came across of using regex, below are the sample of regex pattern I could think of
\[\d{4}\]\s\d{1,3}\s\w{3}\s\d{1,3}
Still, I'm stuck on how to implement it in my codes, anyone can help me on this? Thank you.

Answer 1

Please consider the following code snippet regarding the Regex which might help you to solve your problem.
Private Function Slist(ByVal list As List(Of String)) As List(Of String)
Dim rlist As New List(Of String)
Dim rx As New System.Text.RegularExpressions.Regex("\[\d{4}\]\s\d{1,3}\s\w{3}\s\d{1,3}")
For Each item As String In list
If rx.IsMatch(item) Then
rlist.Add(rx.Match(item).Value)
End If
Next
Return rlist.Distinct.ToList
End Function
Good luck.
Edit 1
Let's make things clear. If you prefer the Regx, consider the following:
Suppose that you have the following lines:
Dim s1 As String = "<p><b>[1]</b> Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum <LINK HREF=""test""><i>NAME</i> [2017] 3 ABCD 247</LINK> [1234] 1 ABC 123; [4567] 2 DEF 456:</p>"
Dim s2 As String = "<p><b>[2]</b> <LINK HREF=""test""><i>NAME</i> [2017] 3 ABCD 247</LINK> [1234] 1 ABC 123 lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.</p>"
If you Regx the pattern:
Dim pat1 As String = "\[\d+\]\s\d\s\D{3}\s\d+"
For Each m As Match In Regex.Matches(s1, pat1)
Console.WriteLine(m.Value)
Next
For Each m As Match In Regex.Matches(s2, pat1)
Console.WriteLine(m.Value)
Next
The output will be 3 matches from both strings (s1 and s2):
[1234] 1 ABC 123
[4567] 2 DEF 456
[1234] 1 ABC 123
Whereas the output of the pattern:
Dim pat2 As String = "(\[\d+\]\s\d\s\D{3}\s\d+.\s\[\d+\]\s\d\s\D{3}\s\d+)"
For Each m As Match In Regex.Matches(s1, pat2)
Console.WriteLine(m.Value)
Next
For Each m As Match In Regex.Matches(s2, pat2)
Console.WriteLine(m.Value)
Next
will be just one match from the first string (s1):
[1234] 1 ABC 123; [4567] 2 DEF 456
hope it's clear now, good luck.

Answer 2

Your XML is malformed, but Regular Expressions is not required here. You essentially are asking to get all the text after the last occurrence of the keyword </LINK>. With that being said, here is a function that does just that:
Private Function Slist(ByVal lines() As String) As IEnumerable(Of String)
Return
From line As String in lines
Where line.IndexOf("</LINK>") > -1
Select line.Substring(line.Substring(line.LastIndexOf("</LINK>") + 8))
End Function
You would pass in the lines from your XML file via read all lines, something like the following:
Dim _slist As IEnumerable(Of String) = Slist(IO.File.ReadAllLines("your-path-here.xml"))