Exclusive OR question

[Frederick Chow]

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.

 

[Tom Ogilvy]

a + b + c = -1

 

[Bob Phillips]

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)

 

[ADG]

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.

 

[Tom Ogilvy]

Fails on

a = False
b = False
c = False

 

[Frederick Chow]

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.

 

[Bob Phillips]

The one I didn't try - <g>

--
HTH

Bob Phillips

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

 

[Dana DeLouis]

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

 

[Dana DeLouis]

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

Dana DeLouis

<snip>