Find the frequency of each element in an array in vb.net

Vb program for Find the frequency of each element in an array. Here more information.

' Include namespace system
Imports System
Imports System.Collections.Generic
Imports System.Collections
'  Vb.net program
'  Count frequency of each element in array 

public Class Occurrence 

    '  Function which is display list elements
    Public Shared Sub display(ByVal arr As Integer())
        Dim i As Integer = 0
        While i < arr.Length
            Console.Write("   " + arr(i).ToString())
        i += 1
        End While
        Console.Write(""& vbLf &"")
    
    End Sub
    '  Count occurrence of given list
    
    Public Shared Sub frequency(ByVal arr As Integer())
        '  Display given list
        display(arr)
        '  Create a empty map
        Dim map As Dictionary(Of Integer, Integer) = 
          New Dictionary(Of Integer, Integer)()
        Dim i As Integer = 0
        While i < arr.Length

            if (map.ContainsKey(arr(i))) Then 
                '  When key exists then update value
                map(arr(i)) = map(arr(i)) + 1
            Else 
                '  Add new element
                map(arr(i)) = 1
            End IF

        i += 1
        End While
        Console.WriteLine("  Occurrence ")
        '   Display calculated result
        For Each entry As KeyValuePair(Of Integer,Integer) In map
            Console.WriteLine("  " + 
                              entry.Key.ToString() + "  :  " + 
                              entry.Value.ToString())
        Next
    
    End Sub
    
    Public Shared Sub Main(ByVal args As String())
        '  Array element
        Dim arr As Integer() = 
        {1, 3, 2, 1, 4, 2, 7, 9, 1, 3, 3, 4, 7}
        frequency(arr)
    
    End Sub

End Class

Output

   1   3   2   1   4   2   7   9   1   3   3   4   7
  Occurrence
  1  :  3
  3  :  3
  2  :  2
  4  :  2
  7  :  2
  9  :  1