Splitting the string except for symbols - regex

Question

I tried using these 2 codes:
Dim splitQuery() As String = Regex.Split(TextBoxQuery.Text, "\s+")
and
Dim splitQuery() As String = TextBoxQuery.Text.Split(New Char() {" "c})
My example query is a dog . Notice there's a single space between dog and .. When I check the length of splitQuery, it gives me 3 and the split words are a, dog, and ..
How can I stop it from counting . and other symbols as word? I want words/terms (alphanumeric) only to be stored in my splitQuery array. Thanks.

Answer 1

I suggest doing that in 2 steps:
Use txt = Regex.Replace(TextBoxQuery.Text, "\W+$", "", RegexOptions.RightToLeft) to remove the non-word characters from the end of the string
Then, split with \s+: splits = Regex.Split(txt, "\s+")
If you prefer to split with any non-word chars, you may use
splits = Regex.Split(Regex.Replace(TextBoxQuery.Text, "^\W+|\W+$", ""), "\W+")
Here, Regex.Replace(TextBoxQuery.Text, "^\W+|\W+$", "") removes non-word chars both at the start and end of string.

Answer 2

you should also be able to create a string of unwanted characters and trim them with a stringsplitoption to RemoveEmptyEntries.
dim unwanted as string = "./?!#"
Dim splitQuery() as string = yourString.Trim(unwanted.tochararray).Split(New Char() {" "c}), StringSplitOptions.RemoveEmptyEntries)

Answer 3

I would tackle this problem in two parts.
I would split up the text by spaces like you're doing
I would then run through that list of words and remove any query terms that are non-alphanumeric.
The following is an example of that:
Imports System.Collections
' ... Your Other Code ...
' A function to determine if a string is AlphaNumeric
Private Function IsAlphaNum(ByVal strInputText As String) As Boolean
Dim IsAlpha As Boolean = False
If System.Text.RegularExpressions.Regex.IsMatch(strInputText, "^[a-zA-Z0-9]+$") Then
IsAlpha = True
Else
IsAlpha = False
End If
Return IsAlpha
End Function
' A function to get the words from the textbox
Private Function GetWords() As String()
' Get a raw list of all words separated by spaces
Dim splitQuery() As String = Regex.Split(TextBoxQuery.Text, "\s+")
' ArrayList to place all words into:
Dim alWords As New ArrayList()
' Loop all words and check them:
For Each word As String In splitQuery
If(IsAlphaNum(word)) Then
' Word is alphanumeric
' Add it to the list of alphanumeric words
alWords.add(word)
End If
Next
' Convert the ArrayList of words to a primitive array of strings
Dim words As String() = CType(alWords.ToArray(GetType(String)), String())
' Return the list of filtered words
return words
End Function
This code does the following:
splits up the textbox's text
declares an ArrayList for the filtered query terms/words
loops through all the words in the split up array of terms/words
it then checks if the term is alphanumeric
If the term is alphanumeric, it is added to the ArrayList. If it's not alphanumeric, the term is disregarded.
Finally, it casts the terms/words in the ArrayList back to a normal String array and returns.
Because this solution uses an ArrayList, it requires System.Collections as an import.