Exclusive OR question
 

Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

a + b + c = -1

--
Regards,
Tom Ogilvy



"Frederick Chow" wrote:

Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

If Not ((a And b) Or (a And c) Or (b And c)) Then


--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Frederick Chow" wrote in message
...
Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

Hi

VBA stores false as 0 and true as -1. You can declare an interger variable
and set it to A+B+C if the result is -1 only one is true.
--
Tony Green


"Frederick Chow" wrote:

Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

Fails on

a = False
b = False
c = False

--
Regards,
Tom Ogilvy


"Bob Phillips" wrote:

If Not ((a And b) Or (a And c) Or (b And c)) Then


--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Frederick Chow" wrote in message
...
Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Thanks for all of you. Really enlightening (N/C)
 

"Frederick Chow" wrote in message
...
Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

The one I didn't try - <g

--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Tom Ogilvy" wrote in message
...
Fails on

a = False
b = False
c = False

--
Regards,
Tom Ogilvy


"Bob Phillips" wrote:

If Not ((a And b) Or (a And c) Or (b And c)) Then


--
HTH

Bob Phillips

(replace somewhere in email address with gmail if mailing direct)

"Frederick Chow" wrote in message
...
Hi all,

Sorry first that my question may not be specifically related to Excel
VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if
there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

Suppose I have three Boolean variables A, B and C. How can I test if there
is exactly one of them is true?
A Xor B Xor C

Would this idea work?

bJustOne = (a Or b) Xor c

--
HTH. :)
Dana DeLouis
Windows XP, Office 2003


"Frederick Chow" wrote in message
...
Hi all,

Sorry first that my question may not be specifically related to Excel VBA,
but I really encountered it when I had to write a VBA function.

Suppose I have three boolean variables A, B and C. How can I test if there
is exactly one of them is true? I found that the following expression

A Xor B Xor C

failed when A = True and B = True and C = True.

Any ideas would be greatly appreciated.

Frederick Chow
Hong Kong.

Exclusive OR question
 

Please disregard! I didn't mean to send that, as it is not correct.

Dana DeLouis

<snip