Sample XSLT to Create Delimited String

1. Map Array to an Element using XSLT

<TargetElement>
    <xsl:for-each select="tns:SourceCollection/tns:SourceElement">
        <xsl:value-of select="." />
        <xsl:if test="position() != last()">
            <xsl:value-of select="','"/>
        </xsl:if>
    </xsl:for-each>
</TargetElement>