Declaring Variables

<xsl:variable> allows you to associate a variable with a string, node list, or result tree fragment.

Variables are "single assignment" (no side effects)

Variables are lexically scoped

Variables assigned inside a conditional only apply inside that conditional. This is rarely correct:

<xsl:if test="$foo">
  <xsl:variable name="bar">...</xsl:variable>
</xsl:if>

Usually, you want to put the conditional inside the variable

<xsl:variable name="bar">
  <xsl:if test="$foo">...</xsl:if>
</xsl:variable>