Count occurance of specific words in a text file in vb.net - vb.net

Question

I'm trying to count the number of an item in a text file, by counting each instance the item was entered into the file earlier on in the program.
I already have the text read from the file and in a text box. The problem is that my current code was just counting the characters in the textbox and not the number of times my desired word was in the file.
For Each desiredword As String In txtContentofFile.Text
intdesiredword = intdesiredword + 1
txtdesiredwordcount.Text = intdesiredword
Next
This counts the characters in the textbox instead of counting the number of desired words. I tried repeatedly before asking help and searched extensively, but I just don't understand what's wrong with my code. Please help :)

Answer 1

You can use Split Function :
C#:
int count = txtContentofFile.Text.Split(desiredword).Length - 1;
VB.net:
Dim count As Integer = txtContentofFile.Text.Split(desiredword).Length - 1

Answer 2

I prefer to use Regular Expressions in this type of situation. They are very tricky to understand but they are extremely powerful and typically faster than other string manipulation techniques.
Dim AllMatchResults As MatchCollection
Try
Dim RegexObj As New Regex(desiredword)
AllMatchResults = RegexObj.Matches(txtContentofFile.Text)
If AllMatchResults.Count > 0 Then
' Access individual matches using AllMatchResults.Item[]
Else
' Match attempt failed
End If
Catch ex As ArgumentException
'Syntax error in the regular expression
End Try
In your case you are looking for the value from AllMatchResults.Count.
Using a great Regular Expression tool like RegexBuddy to build and test the expressions is a great help too. (The above code snippet was generated by RegexBuddy!)

Answer 3

Try this:
Dim text As String = IO.File.ReadAllText("C:\file.txt")
Dim wordsToSearch() As String = New String() {"Hello", "World", "foo"}
Dim words As New List(Of String)()
Dim findings As Dictionary(Of String, List(Of Integer))
'Dividing into words
words.AddRange(text.Split(New String() {" ", Environment.NewLine()}, StringSplitOptions.RemoveEmptyEntries))
findings = SearchWords(words, wordsToSearch)
Console.WriteLine("Number of 'foo': " & findings("foo").Count)
Function used:
Private Function SearchWords(ByVal allWords As List(Of String), ByVal wordsToSearch() As String) As Dictionary(Of String, List(Of Integer))
Dim dResult As New Dictionary(Of String, List(Of Integer))()
Dim i As Integer = 0
For Each s As String In wordsToSearch
dResult.Add(s, New List(Of Integer))
While i >= 0 AndAlso i < allWords.Count
i = allWords.IndexOf(s, i)
If i >= 0 Then dResult(s).Add(i)
i += 1
End While
Next
Return dResult
End Function
You will have not only the number of occurances, but the index positions in the file, grouped easily in a Dictionary.

Answer 4

Try the following code
Function word_frequency(word_ As String, input As String) As Integer
Dim ct = 0
Try
Dim wLEN = word_.Length
Do While input.IndexOf(word_) <> -1
Dim idx = input.IndexOf(word_) + wLEN
ct += 1
input = input.Substring(idx)
Loop
Catch ex As Exception
End Try
Return ct
End Function