## 15.2. Arithmetic OperatorsThe arithmetic operators combine numbers to get new numbers in accordance with the usual rules of arithmetic. As in most computer languages, multiplication and division take precedence over addition and subtraction (in the absence of parentheses). So, for example: 3 + 4 * 2 -- 11 3 * 4 + 2 -- 14 An operand that is a list consisting of one number will be coerced to a number. An operand that is a string representing a number, or a list consisting of one such string, will be coerced to a number. The class of the result of the addition, subtraction, multiplication, and remainder operators is as follows: the result is an integer if the first operand is an integer and if the second operand either is an integer or is a real that can be coerced to an integer without loss of information. Otherwise, the result is a real.
Do not blame AppleScript for the phenomena inherent in doing floating-point arithmetic in any language on any computer. It is the nature of computer numerics that most values can only be approximated. Modern processors are extraordinarily clever about compensating, but rounding operations can easily expose the truth: ` 2.32 * 100.0 div 1 -- 231 ` Similarly, there may be situations where instead of comparing two values for absolute equality, you will do better to test whether the difference between them lies within some acceptable small epsilon.
addition ## addition## Syntax
## DescriptionAdds the operands. The addition operator is not overloaded to perform string concatenation; see "Concatenation Operator" (
subtraction ; unary negation ## subtraction; unary negation## Syntax
## DescriptionSubtracts the second operand from the first, or negates the single operand. Unary negation has very high precedence . On date arithmetic, see Chapter 13.
multiplication ## multiplication## Syntax
## DescriptionMultiplies the operands.
real division ## real division## Syntax
## DescriptionDivides the first operand by the second. Both numbers are treated as reals, and the result is a real.
integer division ## integer division## Syntax
## DescriptionObtains the integer part of a division. Both numbers are treated as reals; the first is divided by the second, and the result is coerced to an integer by throwing away its fractional part. Notice that this is not the same as AppleScript's normal real-to-integer coercion behavior. Thus, the way to get the integer part of a real in AppleScript is ## Example4 div 5 -- 0 (4 / 5) as integer -- 1
remainder ## remainder## Syntax
## DescriptionObtains the remainder from a division. The first operand is divided by the absolute value of the second, and the remainder is returned.
exponentiation ## exponentiation## Syntax
## DescriptionRaises the first number to the power of the second. The result is a real. |

AppleScript: The Definitive Guide, 2nd Edition

ISBN: 0596102119

EAN: 2147483647

EAN: 2147483647

Year: 2006

Pages: 267

Pages: 267

Authors: Matt Neuburg

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