how to determine the size of an object?

Question

Public Class A
    Private aa As Integer
    Dim bb As Integer
    Public cc As Integer
End Class

Public Class B
    Inherits A

    Private dd As Integer
    Dim ee As Integer
    Public ff As Integer
End Class

Public Class C
    Dim oA As New A
End Class

what is the size of the object oA?
and what if Class A and B contain methods?(I meant the size of object)
what if inherited class B contains overridden methods?(size of object)
what if inherited class B contains variables with same name as in Class A?(size of object)

I need theoretical answer. Does those access specifiers Private,Dim,Public make any difference in allocating memory because of their different scopes?
On what basis memory is allotted for a method? etc.

Maybe this can help you? http://stackoverflow.com/questions/324053/find-out-the-size-of-a-net-object — Sergey Gavruk, Aug 22 '11 at 05:44

score 2 · Accepted Answer · answered Aug 22 '11 at 05:56

2

oA is a variable holding a reference, not an object; the size of a reference depends on the platform, but is generally 4 bytes on x86 and 8 bytes on x64
the object referenced by oA is of type A, and has 3 integers, so the size is 12 bytes plus the standard object header
methods do not impact object size (no matter whether they are direct or inherited)
an instance of type B has 6 integers (3 directly, 3 inherited from A); any name overlaps do not impact the fact that they exist - so the size is 24 bytes plus the standard object header

answered Aug 22 '11 at 05:56

Marc Gravell

1,026,079
266
2,566
2,900

what will be the size of object header and what will it depend on? – techBeginner Aug 22 '11 at 06:39
@dotNETbeginner see http://www.simple-talk.com/dotnet/.net-framework/object-overhead-the-hidden-.net-memory--allocation-cost/ – Marc Gravell Aug 22 '11 at 06:47

how to determine the size of an object?

1 Answers1