Binary integers

  • Thread starter Thread starter John Dann
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John Dann

I've obviously got a blind spot for binary arithmetic! Why can't I
say:

Dim x as uint32 = &HFFFFFFFF

(which gives a 'Constant expression not representable' error in
VB2005)

8 characters each of 4 bits should define a 32-bit integer, shouldn't
they? What am I failing to spot/understand?

Is this where integer literals come in - I've seen the term but not a
description?

Dim x as int32 = &HFFFFFFFFI

seems to clear the error though not if it's still declared as a uint.
Is this the recommended way to do what I'm trying to do? (Which is to
define an ARGB colour, but not as a .Net colour type - the third-party
DLL that I need to pass a value to doesn't work directly with .Net
colours.)
 
Use the UI suffix to force an unsigned value (else this is a negative
integer value that can't be used for an unsigned value).

You could also use UInt32.MaxValue...
 
John Dann said:
I've obviously got a blind spot for binary arithmetic! Why can't I
say:

Dim x as uint32 = &HFFFFFFFF

(which gives a 'Constant expression not representable' error in
VB2005)
Click to expand...


In addition to Patrice: The literal at the right is interpreted as an
Integer (not unsigned integer). It's value is -1. -1 can not be stored in an
UInt32. Therefore the exception.


Armin
 
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