Word count

How can we count words in a String using the VB.NET language? Words are delimited by spaces and some types of punctuation.

The easiest way to count words is with a regular expression. We use a Regex with a pattern that matches non-word characters. The Matches() function can be used.

Example

This program imports the System.Text.RegularExpressions namespace. This allows us to use the Regex type directly in the CountWords function.

Info In CountWords, we use the Regex.Matches shared function with the pattern "\S+".

And The pattern means each match consists of one or more non-whitespace characters.

Here We use two String literals as arguments to CountWords. Then we write the word counts that were received.

Result The first sentence, from Shakespeare's play Hamlet, has ten words. The second sentence, from a nursery rhyme, has five words.

Imports System.Text.RegularExpressions

Module Module1
    Sub Main()
        ' Count words in this string.
        Dim value As String = "To be or not to be, that is the question."
        Dim count1 As Integer = CountWords(value)

        ' Count words again.
        value = "Mary had a little lamb."
        Dim count2 As Integer = CountWords(value)

        ' Display counts.
        Console.WriteLine(count1)
        Console.WriteLine(count2)
    End Sub

    ''' <summary>
    ''' Use regular expression to count words.
    ''' </summary>
    Public Function CountWords(ByVal value As String) As Integer
        ' Count matches.
        Dim collection As MatchCollection = Regex.Matches(value, "\S+")
        Return collection.Count
    End Function
End Module10
5

Discussion

Word counting should be close to standard functionality found in programs like Microsoft Word. The function here was checked against Microsoft Word.

Result It was found to have a difference of 0.022% in word counts. This is not perfect, but it is close.

We implemented a word count function in VB.NET. By using the Count property on the MatchCollection, we can count the number of words in a way that is close to other programs.