index.md

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title: id
slug: Web/XPath/Functions/id

---

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The id function finds nodes matching the given ids and returns a node-set containing the identified nodes.

Syntax

id( expression )

Arguments

• expression

  • : If expression is a node-set, then the string value of each node in the node-set is treated as an individual id. The returned node set is the nodes corresponding to those ids. If expression is a string, or anything other than a node-set, then expression is treated as a space-separated list of ids. The returned node set is the nodes corresponding to those ids.

Returns

A node-set containing the node or nodes identified by the given id or ids.

Notes

• The DTD of the XML document determines what attribute is an ID. See XPath 1.0 5.2.1

Defined

XPath 1.0 4.1

Gecko support

Partially supported.