1.vb

This is a book about vb.you could learn this from this book

Imports System.Collections
Imports System

Public Structure Person
    
    Dim Name As String
    Dim Age As Integer
    
End Structure


Public Module Main

	public Sub Main()

		dim dictionary as Hashtable
		dim p as Person

		' Create a Hastable - this is a reference type, so we use New
		' to create the object on the managed CLR heap.

		dictionary = new Hashtable()

		' Setup our Person Structure - This is value type, so we do
		' not use New, and the type is just allocated on the stack.


		p.Name = "Richard Anderson"
		p.Age = 29

		' Add our Person value type to the dictionary.  This will cause
		' the value type to be boxed within a reference type, and added
		' to the dictionary.

		dictionary.Add( "Rich", p )

		' Setup the value type (overwriting the old values)

		p.Name = "Sam Anderson"
		p.Age = 28
		
		' Add our Person value type to the dictionary.  Again, this will cause
		' the value type to be boxed within a reference type and adde to the
		' dictionary.

		dictionary.Add( "Sam", p )

		' Retreive a person by Name.  The CType keyword tells VB that
		' the object type returned by the Item function is a Person
		' type.  Since the Person type is a value type, the CLR knows
		' to unbox the Person type from the returned object type.

		p = CType( dictionary.Item("Rich"), Person )

		' We use the Person type

		Console.WriteLine("Name is {0} and Age is {1}", _
			p.Name, p.Age )
		
		
	End Sub

End Module