Design

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index-of

The index-of function in XQuery is used to find the positions of items in a sequence that are equal to a given search item. It returns a sequence of positions where the specified item occurs.

Syntax

fn:index-of(seqParam, srchParam, collation)

The following table describes the argument for this command:

Argument	Required/Optional	Description
seqParam	Required	The sequence of atomic values to be searched. This sequence can include strings, numbers, and booleans.
srchParam	Optional	The item for which you want to find the index positions within $seqParam .
collation	Optional	A string specifying the collation to use when comparing strings, if required. If omitted, the default collation is used.

Return Value

Returns a sequence of positive integers giving the positions within the sequence

$seqParam

of items that are equal to

$srchParam

. If no matches are found, it returns an empty sequence.

Examples

The following table lists some sample values and return values:

SAMPLE FUNCTION	OUTPUT
fn:index-of( ('a', 'b', 'c'), 'a')	1
fn:index-of( ('a', 'b', 'c'), 'd')	()
fn:index-of( (4, 5, 6, 4), 4)	(1, 4)
fn:index-of( (4, 5, 6, 4), 04.0)	(1, 4)
fn:index-of( ('a', 5, 6), 'a')	1
fn:index-of( (), 'a')	()
fn:index-of( (<a>1</a>, <b>1</b>), <c>1</c> )	(1, 2)