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How can I use XPath to find the minimum value of an attribute in a set of elements?

Asked 2009-07-15T00:11:05.143
33

If I have XML like:

<foo>
  <bar id="1" score="192" />
  <bar id="2" score="227" />
  <bar id="3" score="105" />
  ...
</foo>

Can I use XPath to find the minimum and maximum values of score?

Edit: The tool i'm using (Andariel ant tasks) doesn't support the XPath 2.0 solution.

xml xpath xpath-1.0
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1 Answer

44

Here's a slightly shorter solution.

Maximum:

/foo/bar/@score[not(. < ../../bar/@score)][1]

Minimum:

/foo/bar/@score[not(. > ../../bar/@score)][1]

I've edited the predicate so that it's applicable to any sequence of bar, even if you decide to change the path. Note that parent of attribute is the element to which it belongs.

If embedding these queries in XML files like XSLT or ant scripts, remember to encode < and > as &lt; respecting &gt;.

answered 2009-07-15T07:32:44.493

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