Here is an example where there are new lines and have to validate if the exact text is displayed in the correct order using xpath.

User-agent: *
Disallow: /clickthrough.html
Disallow: /details.html
Disallow: /post-sendtofriend.html

Use normalize-space(), which will throw away the leading and trailing whitespace characters (and condense repeating spaces in the middle of the text into a single space), so that you can compare the normalized text() and use to filter in a predicate.
Here is the xpath code to validate the above text

try
{
selenium.getText("//test[normalize-space()]").Equals("pass the string here");
}
catch(Exception)
{
}


Here is the xpath I want to use regular expression.
Code with out using regular expression:
Assert.IsTrue(selenium.IsElementPresent(“ctl00_5hh5_g5656_675gffg042f_tbSearch”));
Code using regular expression:
Assert.assertTrue(selenium.isElementPresent(“css=input[id$='tbSearch']“));

More…

Here is an example where I have used regular expressions in xpath.
This article includes a code sample that demonstrates how you can use the starts-with XML Path Language (XPath) string function to implement this requirement.

More…

You can use selenium.IsElementPresent(“element”) to see if a particular element is present on the web page. This is a very powerful function in selenium as you can use it with a if condition.
In this example I am first checking if there is an element //td[@class='Selenium'] on the web page. If yes then I click the element //td[@class='Selenium'] and continue checking the other conditions.

More…

Here is an error that I got when I executed the following verifyXpathCount command
<tr>
<td>verifyXpathCount</td>
<td>xpath=//span[@id='ctl00_contentSection_GoogleAFSRight']/div/div[@class='SingleVertical']/a[@class='Heading' and @href]</td>
<td>4</td>
</tr>

More…

verifyXpathCount(xpath, pattern)
Generated from getXpathCount(xpath)
Arguments:
* xpath – the xpath expression to evaluate. do NOT wrap this expression in a ‘count()’ function; we will do that for you.
Returns:
the number of nodes that match the specified xpath

More…