Hello all!

A colleague asked me what was the best (and fastest) approach to concatenate strings between using:

<xsl:variable name="chain" select="concat('Nodename: ', xxx:Resource/@name, etc...)"/>

or this:

<xsl:variable name="chain">
  <xsl:text>Nodename: </xsl:text>
  <xsl:value-of select="xxx:Resource/@name"/>
  etc...
</xsl:variable>

Maybe someone here has done some performance testing and could enlighten me. I wonder if there's a situation where one method is better than the other...

Thanks,

Rushman

Dijkstra's law on Programming and Inertia:

If you don't know what your program is supposed to do, don't try to write it.

__________________
Dijkstra's law on Programming and Inertia:

If you don't know what your program is supposed to do, don't try to write it.

I'd guess it would depend on the implementation, but you are aware that the two operations are different.

The first will create a variable with the concatenated string, the second will create a variable consisting of two text nodes.

/- Sam Judson : Wrox Technical Editor -/

Hi!

Yes I know that it isn't the same thing, but it is going to be used in a <xsl:value-of select="$chain"/> later on.

My guess is that concat() will be more efficient but, as you say, it will depend on implementation.

Maybe Mister Kay could confirm?

Performance obviously depends on the product, but in this case I think it's clear cut: use the select attribute. That directly concatenates strings. The other approach creates a document node having multiple text nodes as its children, only to extract the string value of the document node when it's used as a string. One of my pet hates is

<xsl:variable name="x">
  <xsl:value-of select="some string"/>
</xsl:variable>

partly because it's three lines of code instead of one, and partly because it's three times slower.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thank you Mr. Kay for your quick reply. You rule, as always...

Dijkstra's law on Programming and Inertia:

If you don't know what your program is supposed to do, don't try to write it.