ohoh ... something strange.. have a look

[Steven Pringels 3]

Hi everybody,

the following will also compile on PB/Win but you need to change the print
statements

Why is -1^2 = 1 where it should be -1

FUNCTION PBMAIN() AS LONG

Local eA, eB As Extended
Local nA, nB As Long
eA = -1
eB = 2
Print eA ^ eB

nA = -1
nB = 2
Print nA ^ nB

Print -1^2 ' this one is ok. = -1



END Function

If this is a problem then I will report it to support but maybe there is another
explanation.

Cheers

Steven

[Eric Pearson]

> Why is -1^2 = 1 where it should be -1

Um, negative one squared is equal to positive one.

-- Eric

[Eric Pearson]

...and the reason that PRINT -1^2 displays -1 is "precedence of operators". In a single equation, exponentiation happens first so (1^2) = 1... then the negation makes it negative one.

All is right with the world.

-- Eric

[Steven Pringels 3]

Eric,

One would think so but the following text from the help file indicates the order of precedence.

Another example of the effect of Order of Precedence on an expression follows:

x = -1^2

At first glance, the result of 1 may be the expected result (since -1 * -1 = 1); however, the unary negation operator has a lower precedence than exponentiation, so the expression is evaluated as x& = -(1^2) which gives a result value of -1. As noted above, the use of parentheses can clarify the intended expression:

x = (-1)^2

Also, why does Print -1^2 gives us -1 and the other examples give us 1

[Eric Pearson]

To clarify... the calculation with the variables produces (-1 times -1 =) +1 which is the correct answer.

The PRINT statement is calculating -(1^2) not (-1)^2 just as shown in the example from the Help File that you posted, so it produces -1 not +1.

-- Eric

[Michael Mattias]

Well, until the compiler implements....

#DWIM ON

... using a few more explicit parens and/or variables should solve your problems.

MCM
(Do What I Mean)

[Steven Pringels 3]

Thanks Eric for clarifying this to me

[Steven Pringels 3]

Anyway, when thinking about this. this brings up a problem when trying to
just evaluate using a print statement and actually implementing a routine
using variables...

[Michael Mattias]

this brings up a problem when trying to
just evaluate using a print statement and actually implementing a routine
using variables...

Local eA, eB As Extended
Local nA, nB As Long

[b]LOCAL R  AS EXTENDED[/B] 
eA = -1
eB = 2
R =  eA^eB
'Print eA ^ eB
PRINT R 

nA = -1
nB = 2
R   = nA ^ nB
'Print nA ^ nB
PRINT R
.....