XL: Order of Precedence Causes Unexpected Positive Value

ID: Q132686

The information in this article applies to:

Microsoft Excel for Windows, versions 2.x, 3.x, 4.x, 5.0, 5.0c
Microsoft Excel for the Macintosh, versions 2.x, 3.x, 4.x, 5.0, 5.0a
Microsoft Excel for Windows NT, version 5.0
Microsoft Excel for Windows 95, version 7.0
Microsoft Excel 97 for Windows
Microsoft Excel 98 Macintosh Edition

SYMPTOMS

In Microsoft Excel, when you use a minus sign (-) as a negation operator (for example -1) in a formula, the negation operator has higher precedence than a binary operator. This order of precedence may mean that a formula returns a positive value when you expect it to return a negative value. For example, the following formula


   =-2^2

is evaluated as


   (-2)^2

(that is, with the minus sign evaluated as a negation operator) and returns a positive value, 4.

CAUSE

This behavior is by design of Microsoft Excel. Microsoft Excel uses an order of calculation to evaluate operators in formulas. The order of evaluation of operators dictates that a minus sign (-) used as a negation operator (such as -1) is evaluated before all other operators. Because of this order, the formula =-1^2 represents the value -1 squared, and returns the value 1, a positive value.

WORKAROUND

To preserve the order of operations in a formula, you can specify that the negative symbol in a formula (such as =-1^2) applies to the entire formula by inserting parentheses around the numbers you want to be evaluated first; as in the following example:


   -(2^2)

This formula returns a negative value, -4.

Note that this has been the standard method for evaluating formulas since the first version of Microsoft Excel.

NOTE: This order of operation is different from the order of operation in Lotus 1-2-3.

MORE INFORMATION

For additional information about the order of evaluation of operators, please see the following article in the Microsoft Knowledge Base:

Q25189 Excel: Order of Operations in Formulas

The third-party products discussed here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.

REFERENCES

Microsoft Excel 98 Macintosh Edition

For more information about operator precedence, click Contents And Index on the Help menu (or on the Balloon Help menu if you are using a version of the Macintosh operating system earlier than 8.0), click the Index button in Excel Help, type the following text

operators, formulas

and then click Show Topics. Select the "The order in which Microsoft Excel performs operations in formulas" topic, and click Go To. If you are unable to find the information you need, ask the Office Assistant.

Microsoft Excel 97

For more information about operator precedence in Microsoft Excel, click the Index tab in Microsoft Excel 97 Help, type the following text

operators, evaluation order in formulas

and then double-click the selected text to go to the "The order in which Microsoft Excel performs operations in formulas" topic.

Microsoft Excel 7.0

In Microsoft Excel Help, type the following text

operators, precedence

and then double-click the selected text to go to the "Operator Precedence" topic.

Microsoft Excel 5.0

For more information about "Mathematical Operator Evaluation in Lotus 1.2.3 and Microsoft Excel," click the Search button in Microsoft Excel Help, type the following, and then click Display:

operator

Additional query words: unary minus XL98 XL97 XL7 XL5 XL4 XL3

Keywords : xlformula
Version : MACINTOSH:2.x,3.x,4.x,5.0,5.0a,98; WINDOWS:2.x,3.x,4.x,5.0,5.0c,97; Win95:7.0; winnt:5.0
Platform : MACINTOSH Win95 WINDOWS winnt
Issue type : kbprb