How can I calculate the absolute value of a number in XSLT?

Question

I have

<xsl:value-of select="DifferenceInDays" /> 

DifferenceInDays can be negative or positive, I want to display it as positive. How can I do this?

Answer 1

In XPath 1.0 use the following expression:

   $vNum*($vNum >=0) - $vNum*($vNum < 0)

In case this expression is embedded in an XSLT (XML) attribute, the < character must be escaped:

   $vNum*($vNum >=0) - $vNum*($vNum < 0)

In XPath 2.0 (XSLT 2.0) use the abs() function.

Answer 2

This can be achieved using the xpath abs function.

<xsl:value-of select="abs(DifferenceInDays)"/>

Answer 3

diffInDays * (1 - 2*(diffInDays < 0))

Answer 4

Some of the answers are complicating life way too much for XSLT 1.0 it's actually much simpler. Using the number formatting you can define a structure for Positive and Negative numbers, the default negative is -0 however you can define your own.

<xsl:value-of select='format-number(DifferenceInDays,"0;0")'/>

The above code will show the absolute value of Difference in Days just by using the provided formatting function.