Returns true if the string $arg1 contains $arg2 as a
substring, taking collations into account.
fn:contains( $arg1 as xs:string?,$arg2 as xs:string?xs:booleanfn:contains( $arg1 as xs:string?,$arg2 as xs:string?,$collation as xs:stringxs:booleanIf the value of $arg1 or $arg2 is the empty sequence, or
contains only ignorable collation units, it is interpreted as the zero-length
string.
If the value of $arg2 is the zero-length string, then the function returns
true.
If the value of $arg1 is the zero-length string, the function returns
false.
The collation used by this function is determined according to the rules in .
The function returns an xs:boolean indicating whether or not the value of
$arg1 contains (at the beginning, at the end, or anywhere within) at
least one sequence of collation units that provides a minimal match to the
collation units in the value of $arg2, according to the collation that is
used.
Minimal match is defined in .
The collation used in these examples, http://example.com/CollationA is a
collation in which both "-" and "*" are ignorable collation units.
"Ignorable collation unit" is equivalent to "ignorable collation element" in .
The expression fn:contains ( "tattoo", "t") returns true().
The expression fn:contains ( "tattoo", "ttt") returns false().
The expression fn:contains ( "", ()) returns true().
The expression fn:contains ( "abcdefghi", "-d-e-f-",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:contains ( "a*b*c*d*e*f*g*h*i*", "d-ef-",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:contains ( "abcd***e---f*--*ghi", "def",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:contains ( (), "--***-*---",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
A dynamic error may be raised if the specified collation does not support collation units.