index.md

---

title: namespace-uri
slug: Web/XPath/Functions/namespace-uri

---

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The namespace-uri function returns a string representing the namespace URI of the first node in a given node-set.

Syntax

namespace-uri( [node-set] )

Arguments

• node-set (optional)

  • : The namespace URI of the first node in this node-set will be returned. If this argument is omitted, the current context node will be used.

Returns

A string representing URI of the namespace in which the given node resides.

Notes

• If the given node does not have a specified namespace, the returned string will be an empty string.

• For nodes other than element and attribute nodes, the returned string will always be an empty string.

Defined

XPath 1.0 4.1

Gecko support

Supported.