HashTable stores a Key Value pair type collection of data . We can retrive items from hashTable to provide the key . Both key and value are Objects.

The common functions using in Hashtable are :

Add : To add a pair of value in HashTable

Syntax : HashTable.Add(Key,Value)

Value : The value of corrosponding key

ContainsKey : Check if a specified key exist or not

Synatx : HashTable.ContainsKey(key)

Key : The Key value for search in HahTable

ContainsValue : Check the specified Value exist in HashTable

Synatx : HashTable.ContainsValue(Value)

Value : Search the specified Value in HashTable

Remove : Remove the specified Key and corrosponding Value

Syntax : HashTable.Remove(Key)

Key : The argument key of deleting pairs

The following source code shows all important operations in a HashTable

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, 
	ByVal e As System.EventArgs) Handles Button1.Click
        Dim weeks As New Hashtable
        Dim day As DictionaryEntry
        weeks.Add("1", "Sun")
        weeks.Add("2", "Mon")
        weeks.Add("3", "Tue")
        weeks.Add("4", "Wed")
        weeks.Add("5", "Thu")
        weeks.Add("6", "Fri")
        weeks.Add("7", "Sat")
        'Display a single Item
        MsgBox(weeks.Item("5"))
        'Search an Item
        If weeks.ContainsValue("Tue") Then
            MsgBox("Find")
        Else
            MsgBox("Not find")
        End If
        'remove an Item
        weeks.Remove("3")
        'Display all key value pairs
        For Each day In weeks
            MsgBox(day.Key  "  --  "  day.Value)
        Next
    End Sub
End Class