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.