map:keys - XPath XQuery Reference

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XPath/XQuery keys function

Summary

Returns a sequence containing all the keys present in a map

Signature

map:keys(

$map as map(*)

) as xs:anyAtomicType*

Properties

This function is nondeterministic-wrt-ordering, context-independent, and focus-independent.

Rules

The function map:keys takes any map as its $map argument and returns the keys that are present in the map as a sequence of atomic values, in implementation-dependent order.

The function is non-deterministic with respect to ordering (see ). This means that two calls with the same argument are not guaranteed to produce the results in the same order.

The expression map:keys(map{1:"yes", 2:"no"}) returns (1,2).

The number of items in the result will be the same as the number of entries in the map, and the result sequence will contain no duplicate values.