在XSL中对变量作加法

在XSL中对变量作加法：

如果使用的转换器只支持XSLT 1.0，则：

<xsl:variable name="n1">
<xsl:choose>
<xsl:when test="number($t1) = number($t1)">
<xsl:value-of select="$t1"/>
</xsl:when>
<xsl:otherwise>0</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:variable name="n2">
<xsl:choose>
<xsl:when test="number($t2) = number($t2)">
<xsl:value-of select="$t2"/>
</xsl:when>
<xsl:otherwise>0</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<xsl:variable name="temp1" select="$n1 + $n2"/>

如果XSLT parser支持XSLT 2.0：  

XSLT 2.0 makes it easier because of the conditional expressions in XPath 2.0. You can do:

<xsl:variable name="n1"
select="if (number($t1) = number($t1)) then $t1 else 0" />
<xsl:variable name="n2"
select="if (number($t2) = number($t2)) then $t2 else 0" />
<xsl:variable name="temp1" select="$n1 + $n2" />

Depending on how you're getting the values of $t1 and $t2 (and the final definition of if-absent()) it might also be possible to use the if-absent() function:

<xsl:variable name="temp1" select="if-absent($t1, 0) + if-absent($t2, 0)" />