XPath operator
Union |
Combines two node-sets into one, in document order and without duplicates. It only works on node-sets.
The union operator merges node-sets. The result is in document order with duplicates removed, regardless of the order the operands were written in.
It is the only way to select alternatives in XPath 1.0 — there is no | inside a name test, so you cannot write //(a|b).
- Syntax
node-set | node-set- Returns
- node-set
- Kind
- Operator
- Version
- XPath 1.0 (libxml2)
Worked examples
Each result below is what the evaluator returned, asserted on every test run. An empty result means an empty node-set — which is an answer, not an error.
The sample documents
Every example on this page runs against this document. The sitemap one is namespaced on purpose — almost every real XML document is, and that changes which expressions match.
<?xml version="1.0" encoding="UTF-8"?>
<order id="A-1001" tier="gold">
<customer country="NO">Ada Lovelace</customer>
<lines>
<line sku="WIDGET-1" qty="2"><price>14.50</price></line>
<line sku="WIDGET-2" qty="1"><price>39.00</price></line>
<line sku="GIFT-WRAP" qty="1"><price>0.00</price></line>
</lines>
<note> Deliver after 09:00 </note>
</order>Related
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