如何通过 XPath 选择第一个和最后一个元素? [英] How to select first and last elements via XPath?
问题描述
这是一个示例 XML,我试图弄清楚如何选择第一个节点值并退出循环.如果我使用以下 XSLT 标记
Here is a sample XML, and I am trying to figure out how to select first node value and exit the loop. If I use following XSLT tag
<xsl:value-of select="fruits/fruit"/>
它返回苹果芒果香蕉"但预期结果应该是苹果"
it returns "apple mango banana" but expected result should be "apple"
<fruits>
<fruit>apple</fruit>
<fruit>mango</fruit>
<fruit>banana</fruit>
</fruits>
我还想选择最后一个 fruit
而不知道先验存在多少 fruit
.所以,对于上面的例子,我想在不知道有 3 个 fruit
元素的情况下返回banana".
I'd also like to select the last fruit
without knowing how many fruit
exist a priori. So, for the above example, I'd like to return "banana" without knowing that there are 3 fruit
elements.
推荐答案
第一
您可以通过fruit[1]
选择第一个fruit
(根fruits
元素)的值:
First
You can select the value of the first fruit
(of the root fruits
element) via fruit[1]
:
<xsl:value-of select="(/fruits/fruit)[1]"/>
将根据要求返回 "apple"
.
您可以通过fruit[last()]
选择最后一个fruit
的值:
You can select the value of the last fruit
via fruit[last()]
:
<xsl:value-of select="(/fruits/fruit)[last()]"/>
将根据请求返回 "banana"
而不知道先验存在多少水果.
will return "banana"
as requested without knowing how many fruits exist a priori.
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