CODEWITHSUNDEEP
.netvb.netclassobject
techBeginner
techBeginner

Reputation: 3850

how to determine the size of an object?

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.

Upvotes: 0

Views: 295

Answers (1)

Marc Gravell
Marc Gravell

Reputation: 1064014

  • 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

Upvotes: 2

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