Question

I have two text files with various columns, each column is separated by a tab (” “). What I’m trying to do is the following:-

• If the values in text file 2 column 1 does not contain any value in text file 1 column 1 then add that field to text file 2 and add a 1 to the second column, like so

  String 1

• If the value in text file 2 column 1 already appears in text file 1 columns 1 then just add +1 to the value, so if the above value is already in Text File 1 Column 1 and Text File 2 Column 1 then it would appear as.

  String 2

And if it was to happen again then

String 3

and so on.

I have the following coding so far.

Dim lines1 As New List(Of String)(IO.File.ReadAllLines("File1"))
Dim lines2 As New List(Of String)(IO.File.ReadAllLines("File2"))
IO.File.WriteAllLines("File2", lines1.ToArray) & +1)

Update

Dim lines1 As New List(Of String)(IO.File.ReadAllLines("D:\Test\File6.txt"))
        Dim lines2 As New List(Of String)(IO.File.ReadAllLines("D:\Test\File5.txt"))

        Dim values As New Dictionary(Of String, Integer)()
        For Each line As String In lines1
            Dim fields() As String = line.Split(" "c)
            If fields.Length > 1 Then
                values(fields(0)) = Integer.Parse(fields(1))
            End If
        Next

        For Each line As String In lines2
            Dim fields() As String = line.Split(" "c)
            If fields.Length > 0 Then
                If values.ContainsKey(fields(0)) Then
                    values(fields(0)) = values(fields(0)) + 1
                Else
                    values(fields(0)) = 1
                End If
            End If
        Next

        lines1.Clear()
        For Each pair As KeyValuePair(Of String, Integer) In values
            lines1.Add(pair.Key + " " + pair.Value.ToString())
        Next

        IO.File.WriteAllLines("D:\Test\File6.txt", lines1.ToArray)

I use the above coding, but it removes the second column?

Answer 1

I would recommend using a dictionary to store the key/value pairs in your first text file. Then, you can easily search and modify the data in the dictionary as you parse the data in the second text file. For instance:

Dim lines1 As New List(Of String)(New String() {"A a 1", "B b 2", "C c 3"})
Dim lines2 As New List(Of String)(New String() {"A a", "D d"})

Dim values As New Dictionary(Of String, Integer)()
For Each line As String In lines1
    Dim fields() As String = line.Split(" "c)
    If fields.Length > 2 Then
        values(fields(0) + " " + fields(1)) = Integer.Parse(fields(2))
    End If
Next

For Each line As String In lines2
    Dim fields() As String = line.Split(" "c)
    If fields.Length > 1 Then
        Dim key As String = fields(0) + " " + fields(1)
        If values.ContainsKey(key) Then
            values(key) = values(key) + 1
        Else
            values(key) = 1
        End If
    End If
Next

lines1.Clear()
For Each pair As KeyValuePair(Of String, Integer) In values
    lines1.Add(pair.Key + " " + pair.Value.ToString())
Next