XPath Syntax Quick Reference

This topic provides a quick reference for XPath expression syntax.

Axes

XPath provides the following axes:

ancestor

ancestor-or-self

attribute

child

descendant

descendant-or-self

following

following-sibling

namespace

parent

preceding

preceding-sibling

self

Node Tests

XPath provides the following node tests:

* selects all nodes of the specified name. For the attribute axis, attributes are selected. For the namespace axis, namespace nodes are selected. For all other axes, element nodes are selected.

comment() selects all comment nodes.

element_name selects all element_name nodes.

node() selects all nodes.

processing-instruction(["some_literal "]) selects all processing instructions. If some_literal is specified, processing-instruction() selects all processing instructions with some_literal as their name.

text() selects all text nodes.

Filters

A filter specifies a constraint on a node set with respect to an axis to produce a new node set.

Location Steps

A location step has the following format:


AxisSpecifier `::`NodeTest `[`Filter `][`Filter `]...`

XPath Expression

An XPath expression has one of the following formats:


LocationStep[/LocationStep]... FunctionCall()[Filter]/LocationStep[/LocationStep]... (Expression)[Filter]/LocationStep[/LocationStep]...

A function call or an XPath expression in parentheses can appear only at the very beginning of an XPath expression. An expression in parentheses always returns a node set. Any function that appears at the beginning of an XPath location step expression must return a node set.

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