Dr. Dobb's is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Channels ▼

Web Development

Comparing LINQ-to-XML with XPath

Paul Kimmel is an application architect and author of more than a dozen books, including LINQ Unleashed for C#, on which this article is based. Courtesy Pearson Education, InformIT. All rights reserved.

A few years ago, I wrote a Blackjack game. The game uses statistics from a book on expert play and coaches the player in the statistically best play based on the player's and dealer's hands. (The game and source is available from my website at www.softconcepts.com.) The game was good enough that a programmer from Harrah's in Biloxi asked to use the source, and my understanding is that it is a pillow favor provided at the casino. In this article, game statistics from a round of play were saved as an XML file and that file is used for the demos. (You can download the game and save your own statistics or use the XML provided in Listing One.)

<?xml version="1.0" encoding="utf-8"?>
  <Player Name="Player 1">
       <AverageAmountLost>-28.125</AverageAmountLost>      <AverageAmountWon>30.681818181818183</AverageAmountWon>
Listing One: Statistics from a Round of Play in the Blackjack Game Saved to an XML File

Examples of how to use the cards.dll are all over the web, including in some of my articles, such as Programming for Fun and Profit -- Using the Card.dll.

The basic flow of the subsections that follow is that you are shown some code that uses LINQ-to-XML to query nodes followed by an equivalent XPath query that accomplishes the same goal. (You don't need both; in practice, use one or the other.)

Related Reading

More Insights

Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Dr. Dobb's encourages readers to engage in spirited, healthy debate, including taking us to task. However, Dr. Dobb's moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing or spam. Dr. Dobb's further reserves the right to disable the profile of any commenter participating in said activities.

Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.