CODEWITHSUNDEEP
javaseleniumxpathselenium-webdriver
LoveJavaTwo
LoveJavaTwo

Reputation: 225

last() is not applied

I am using Selenium and Java to write a test, below is my DOM:

<body>    
<div class='t'><span>1</span></div> 
<div class='t'></div> 
<div class='t'><span>2</span></div> 
<div class='t'><span>3</span></div> 
<div class='t'><span>4</span></div> 
<div class='t'><span>5</span></div> 
<div class='t'><span>6</span></div> 
<div class='t'><span>7</span></div> 
<div class='tt'></div> 
</body>

when I use: //div[@class='t'][last()] I get:

<div class="t"><span>7</span></div>

but when I use: //div[@class='t' and last()] I get:

<div class="t"><span>1</span></div>
<div class="t"/>
<div class="t"><span>2</span></div>
<div class="t"><span>3</span></div>
<div class="t"><span>4</span></div>
<div class="t"><span>5</span></div>
<div class="t"><span>6</span></div>
<div class="t"><span>7</span></div>

it's like last() is not applied to the second xpath, why?

Upvotes: 2

Views: 143

Answers (1)

Andrew Regan
Andrew Regan

Reputation: 5113

//div[@class='t'][last()] ... means pick the element from the list of matches (where @class='t') whose index is last, which is what you want.

With //div[@class='t' and last()], the already-calculated value of last() is applied for each match in the list purely on the basis of being != 0, and it will cause the div matcher to return FALSE only if last() is zero. In other words, the last() does not get used to select a single node from the list. That's definitely not what you want.

For example: if last() evaluates to 5, //div[@class='t' and 5] will return every matching element in the list because 5 != 0.

The net result is that if any nodes are matched (last() > 0), all of them will be returned.

See also: XSLT getting last element

Upvotes: 3

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