How can I find the link URL by link text with XPath?

Question

I have a well formed XHTML page. I want to find the destination URL of a link when I have the text that is linked.

Example

Answer 1

Think of the phrase in the square brackets as a WHERE clause in SQL.

So this query says, "select the "href" attribute (@) of an "a" tag that appears anywhere (//), but only where (the bracketed phrase) the textual contents of the "a" tag is equal to 'programming questions site'".