试图获取最后一个 TABLE 元素（xpath）

Question

I've got an html document and am trying to access the last TABLE element.

If I do the following - I get the correct snapshot length of 5.

var headings = document.evaluate( ".//table[@class='blue']",document.body, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,null);

Looking at the HTML page structure - 2 of the TABLES captured by the xpath are nested

TABLE TABLE TABLE TABLE TABLE << this is what I'm interested in.

There are only 5 tables in the document with class='blue'

I'd like access to the last one - so I did:

var headings = document.evaluate( ".//table[@class='blue'][last()]",document.body, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,null);

It returns an unexpected length of 4 - I was expecting 1.

The last snapshot entry (idx=3) is the correct TABLE. With last() in, it seems to be skipping 1 table that's hidden.

How can I just get the last TABLE element?

Looking at the html document - there are 5 tables with class='blue' and two of them are nested

TABLE
TABLE
  TABLE
  TABLE
TABLE   <<-- I'm interested in this one

I tried

var headings = document.evaluate( ".//table[@class='blue' and position() = last()]",document.body, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,null);

and it returned a length of 3 - the middle three tables.

Answer 1

Looks like the correct answer is

"(.//table[@class='blue'])[last()]"

needed the perens around table .

Is there any inefficiencies?

Better way to do the same?