问题
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?
回答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.
回答2:
This can be achieved using the xpath abs function.
<xsl:value-of select="abs(DifferenceInDays)"/>
回答3:
diffInDays * (1 - 2*(diffInDays < 0))
回答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.
来源：https://stackoverflow.com/questions/804421/how-can-i-calculate-the-absolute-value-of-a-number-in-xslt