Check whether one string contains another.

Related Syntax Constructs

The following construct(s) refer to this construct:

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Syntax

fn:contains(string $string, string? $searchString) => boolean

fn:contains(string $string, string? $searchString, string $collation) => boolean

Description

This function checks whether the value of $string contains the value of $searchString anywhere. It returns true if it is found and false if not. There are some special cases in which this function returns the following values:

true	the value of $string is a string of length zero
false	the value of $searchString is a string of length zero

It is an error if either string value is an empty sequence.

Arguments

$string	string value
$searchString	string value that is searched for in $string
$collation	optional valid collation string literal

Examples

• Is "ino" in "Tamino"?

  contains("Tamino", "ino")

  The function returns true, since "ino" is obviously contained in "Tamino".

• Is the empty string part of another empty string?

  contains("", "")

  The function returns true.