# XQuery - Sequence Function-index-of Function - XQuery

The index-of function is used to track items in the given sequence. It returns integers to indicate the availability of items in a given sequence.

## Input Parameters

• $seq − provided sequence. Sequence can contain 0 or more items. •$target − item whose index is to be returned.

## Verify the Result

In order to test the above-mentioned functionality, replace the contents of books.xqy (mentioned in Environment Setup chapter) with the above XQuery expression and execute the XQueryTester java program to verify the result.