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count

The count function in XQuery is used to determine the number of items in a sequence.

fn:count(arg)

The following table describes the argument for this command:

Argument	Required/Optional	Description
arg	Required	The sequence of items to count.

The function returns an

xs:integer

representing the number of items in the sequence.

The

count()

function operates on sequences, including numbers, strings, and XML nodes.

If the input sequence is empty, it returns

If all values passed to this function are NULL, it returns 0.

It does not count individual characters within a string, only top-level sequence items.

If you have an XML document containing a list of books and you want to count how many books are listed:

<library>
    <book>Book A</book>
    <book>Book B</book>
    <book>Book C</book>
</library>

Use the following XQuery:

let $books := doc("library.xml")/library/book
return fn:count($books)

The output is

The following table lists some additional sample values and return values:

Watch

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