负数 XSLT 的 Mod 操作

Question

I am trying to put logic in XSL to get the value.

1+ mod(DateDifference ,number)

DateDifference can be positive or a negative number and formula should work in all scenarios whether date diff is +ve , -ve or 0 .

This formula in XSL is not working for below values

DateDifference= -33
Number=8

The result, I am getting in MS Excel with the same formula is 7 but the XSL result is -1 .

Can anyone suggest me the correct way or syntax for using the number for all possible DateDifference values?

Answer 1

Different languages use different definitions for modulo operations. In most programming languages, the mod function is defined as:

n mod d  =  n - d * trunc(n / d) 

(where trunc() means truncation to 0 decimal places) and this is also the algorithm implemented in XSLT.

Donald Knuth proposed:

n mod d  =  n - d * floor(n / d) 

and this is the algorithm currently implemented in Excel. To get the same result in XSLT, use:

n - d * floor(n div d)

Answer 2

For handling negative and positive mod in XSL

<xsl:function name="fun:mod" as="xs:string">
        <xsl:param name="int1" as="xs:integer"/>
        <xsl:param name="int2" as="xs:integer"/>
        <xsl:value-of select="($int1 mod $int2 + $int2) mod $int2"/>


    </xsl:function>