array finding

array finding

• Michael J Brown

  ok but how do i use it. how do i get from that bit of code the number in the array and how many of them there are. so number 1 and there is 3 of them.
  

• Gurpreet Singh Gill

  This should work, a few minor changes.

  Public Class Form1

  
      Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
          Dim x As New Dictionary(Of Integer, Integer) '//Create a dictionary
          Dim MyNumbers As Integer() = {1, 1, 1, 1, 2, 3, 3, 3, 4} ' Our numbers

          x = BrainTickler(MyNumbers) '//Call the method to total them

          '//Build a string of the results
          Dim strContents As String = ""
          For Each a As KeyValuePair(Of Integer, Integer) In x
              strContents = strContents & a.Key.ToString & vbTab & a.Value.ToString & vbCrLf
          Next

          '//Display the results
          MsgBox(strContents)

      End Sub

  
      Private Function BrainTickler(ByVal MyNumbers As Integer()) As Dictionary(Of Integer, Integer)

          Dim MyCounts As New Dictionary(Of Integer, Integer) ' Keeps track of our counts
          Dim I As Integer
          For I = 0 To MyNumbers.Length - 1
              If MyCounts.ContainsKey(MyNumbers(I)) = False Then ' Check to see if the number exists
                  MyCounts.Add(MyNumbers(I), 1) ' Add key to count and set count to 1 since we just found it
              Else
                  MyCounts(MyNumbers(I)) = MyCounts(MyNumbers(I)) + 1    ' Increment the counter
              End If
          Next
          Return MyCounts
      End Function
  End Class
  

  
  

• Peter Rook

  Here is one cute way of doing it. And the explanation of how it works.
  We have a dictionary which basically can contain a key. Each key is used to lookup a value. In this case we are going to use the numbers found in our array (MyNumbers) as the key. The values that will be looked up will be the count.
  So we declare our variables and then we go through our for loop.
  For each number in MyNumbers we check to see if this number exists as a key in our Counter array. If it doesn't we add it and set it's count to 1 since we found one occurrance. If it already exists we simply increment the counter.
  So first pass we have a 1 and we see if it's in MyCounts -which i'ts not so we add it . Second pass we find another one and see if it is in which it is so we simply incremement that. Repeat that for 3rd and 4th pass and soon we have 4 1's . etc
  
  Private Function BrainTickler() As Dictionary(Of Int32, Integer)
  Dim MyNumbers As Integer() = {1, 1, 1, 1, 2, 3, 3, 3, 4} ' Our numbers
  Dim MyCounts As New Dictionary(Of Int32, Integer) ' Keeps track of our counts
  Dim I As Int32
  For I = 0 To MyNumbers.Length - 1
  If MyCounts.ContainsKey(MyNumbers(I)) = False Then ' Check to see if the number exists
  MyCounts.Add(MyNumbers(I), 1) ' Add key to count and set count to 1 since we just found it
  Else
  MyCounts(MyNumbers(I)) = MyCounts(MyNumbers(I)) + 1 ' Increment the counter
  End If
  Next
  BrainTickler = MyCounts
  Dim P As Int32
  End Function
  
  Hope that helps.
  
  
• array finding