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"Antonio Vernucci" wrote in
: Do you realise that the '-' in both expressions are quite different in meaning, one is a unary negation operator, the other is the binary subract operator. I realise, but Microsoft apparently does not: - for Excel: (-2^2 + 8) = 12 - for Visual Basic: (-2^2 + 8) = 4 They look pretty much the same Not to a programmer! I would expect that some programmers may get confused, due to the inconsistency of software products of the same company. Do not assume that all languages or all products use the same operator precedence rules. The Excel rules are spelled out in the Excel help. The key thing is that there is a difference in the meaning of '-' in the uses as the negation operator and subtraction operator, same symbol, two meanings, you need to understand that when looking in the list of operator precedence. Excel spells out clearly that unary negation has higher precedence than exponentiation, and subtraction is lower than both... so keep that in mind when writing formulae. If you are writing VB, use the precedence rules for VB. The VB rules clearly state that exponentiation has higher precedence than negation, and subtraction is lower. This may have its roots before the existence of Microsoft. Many languages do not have an exponentiation operator, requiring functions instead (often pow()). Such use eliminates the operator precedence issue. PERL does have an exponentiation operator, and it is higher precedence than unary + and -. FORTRAN90 does have an exponentiation operator, and it is higher precedence than unary + and -. It is part of the programming landscape... algebraic expressions are not universal, they need to be written for the specific language. Now, I hear that you think that is a bad idea, but it isn't likely to change. It is most unlikely that a new version of any language will change operator precedence, it has too many issues. Owen |
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