Sizeof in C++. what is that in VB ?

[DavidBG]

Hi, it is about the syntax key SIZEOF(...) in C++.
I am looking for a VB predefined method which does the same as SIZEOF in C++.

e.g Num1 = SizeOf(Array1) //return the size of the Array1

How to write this in VB.

[ccoder]

In C and C++, sizeof is resolved in the pre-compile stage along with #define, #include, etc. When the source is passed to the compiler, the statement "Num1 = SizeOf(Array1);" will have been replaced with "Num1 = 100;" (or whatever the byte size is for Array1). The size is obtained from the symbols table. All that sizeof does is eliminate the need for a runtime call.

I don't know that VB has a similar functionality. If it does, I would too be interested in knowing what it is. In the mean while, I will continue to use the LenB function.

HTH

I don't think there is a similar function in VB (but I could be mistaken, you might be able to do it with API calls or something). In VB you can use the Len() function to return either the length of a string or the number of bytes required to store a non-string like:


Dim lngExample As Long

MsgBox Len("Hello World!") ' Would return 12.
MsgBox Len(lngExample) ' Would return 4.


You could possibly combine Len() with the LBound() and UBound() functions to determine the size of an array. LBound() returns an arrays lower bounds and UBound() gives its upper.

Good luck,
Paul

[DavidBG]

Thanks to CCoder and PWNettle.

However I am using wininet API function and structure type
of Microsoft example. The following code is in a VB module.

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Public Type INTERNET_BUFFERS
dwStructSize As Long ' used for API versioning.
' Set to sizeof
(INTERNET_BUFFERS)
Next As Long
lpcszHeader As Long
dwHeadersLength As Long
dwHeadersTotal As Long
lpvBuffer As Long
dwBufferLength As Long
dwBufferTotal As Long
dwOffsetLow As Long
dwOffsetHigh As Long
End Type
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''

In a VB function, I initiate a variable of this INTERNET_BUFFERS type. as:

Dim sBufferOUT AS INTERNET_BUFFERS

sBufferOUT.dwHeaderLength = 0
sBufferOUT.dwHeaderTotal = 0
sBufferOUT.dwBufferLength = 0
sBufferOUT.dwOffsetLow = 0
...etc , but then
sBufferOUT.dwStructSize = ?? sizeof something ??

I dont know how to assign it a value, like the above Microsoft instruction

Thanks for help

[ccoder]

Use sBufferOUT.dwStructSize = LenB(sBufferOUT)