How do I reassign a variable in XSLT?

Question

I want to be able to do some basic reassignments to variables in XSLT. How can this be achieved?

I just want to be able to convert this to XSLT (ignoring the appendM

Answer 1

XSLT is a declarative language, it doesn't use stateful variables. You need to work out how to express your output as a function of the input, rather than thinking of a way to give low-level procedural instructions to the computer.

In your case it seems very straightforward; just use different variables:

if(currentMonth + count > 12) {
    m2 = (currentMonth + count) - 12; 
    if (m2 < 10) then appendMonthWithZero(m2) else m2;
} else {
    currentMonth
}

Answer 2

I just almost believe the viewpoint in other replies， before I test the follow code that can really run well in xlst proccessor saxon-he 9.8.0.12 my code ：

    <?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:map="http://www.w3.org/2005/xpath-functions/map"
    exclude-result-prefixes="xs map"
    version="2.0">

    <xsl:template match="/">
        <xsl:variable name="i1" select="123" as="xs:integer"/>
        <xsl:variable name="s1" select="'abcd'" as="xs:string"/>
        <xsl:variable name="d1" select="234.5" as="xs:float"/>

        <!-- we test that variable v1 can be assignment multi times and it is ok.  -->
        <xsl:variable name="v1" select="$i1"/>
        v1 is: <xsl:value-of select="$v1"/>
        <xsl:variable name="v1" select="$s1"/>
        v1 is: <xsl:value-of select="$v1"/>
        <xsl:variable name="v1" select="$d1"/>
        v1 is: <xsl:value-of select="$v1"/>

        <xsl:variable name="map1" select="map{'haha':119, 'good':110}"/>
        <xsl:variable name="map2" select="map:put($map1, 'go', 122)"/>
        <xsl:variable name="map1" select="map:put($map2, 'hello', 999)"/>
        map1(haha) is <xsl:sequence select="$map1?haha"/>
        map1(haha) is <xsl:sequence select="$map1?go"/>
        map1(hello) is <xsl:sequence select="$map1?hello"/>
    </xsl:template>

</xsl:stylesheet>

the screenshort of running result

for your question. the solution maybe like that:

<xsl:template match="/" priority="20">
        <xsl:variable name="month" select="9"/>
        <xsl:variable name="count" select="5"/>
        <xsl:variable name="month" select="if (($month + $count) &gt; 12) then ($month + $count) mod 12 else $month"/>
        month is:<xsl:value-of select="$month"/>
</xsl:template>