Creating Arithmetic Expressions

Besides primary expressions, XPath 2.0 also supports arithmetic operators for addition, subtraction, multiplication, division, and modulus . These operators are represented this way (note that instead of using the / symbol for division, which can be interpreted as markup, XPath 2.0 uses the div operator):

  • + Addition

  • - Subtraction and Negation

  • * Multiplication

  • div Division

  • idiv Integer division

  • mod Modulus

USING THE SUBTRACTION OPERATOR

In XPath 2.0, you must precede a subtraction operator with a space, because "-" is a legal name character. In other words, x-y can be interpreted as a name, whereas x - y is an expression involving a subtraction operation.


The idiv operator requires its operands to be of type xs:integer and returns a result of type xs:integer , rounded toward zero. And the mod operator returns the remainder after a division (for example, 16 mod 3 is 1).

Here are some examples of arithmetic expressions:

  • 4 * 2 returns 8

  • 33 + 11 returns 44

  • -5 div 2 returns 2.5

  • -5 idiv 2 returns 2

  • $temp + 12 returns 72 if $temp holds 60

  • -(20 + 6) returns 26

SUBTRACTING DATE VALUES

In XPath 2.0, if you subtract two date values, the result is of the xdt:dayTimeDuration type.




XPath. Navigating XML with XPath 1.0 and 2.0 Kick Start
XPath Kick Start: Navigating XML with XPath 1.0 and 2.0
ISBN: 0672324113
EAN: 2147483647
Year: 2002
Pages: 131

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