Returns true if the string $arg1 contains $arg2 as a leading
substring, taking collations into account.
fn:starts-with( $arg1 as xs:string?,$arg2 as xs:string?xs:booleanfn:starts-with( $arg1 as xs:string?,$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 and
the value of $arg2 is not the zero-length string, then 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 starts with a sequence of collation units that provides a
match to the collation units of $arg2 according to the
collation that is used.
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:starts-with("tattoo", "tat") returns true().
The expression fn:starts-with ( "tattoo", "att") returns false().
The expression fn:starts-with ((), ()) returns true().
The expression fn:starts-with ( "abcdefghi", "-a-b-c-",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:starts-with ( "a*b*c*d*e*f*g*h*i*", "a-bc-",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:starts-with ( "abcd***e---f*--*ghi", "abcdef",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:starts-with ( (), "--***-*---",
"http://www.w3.org/2013/collation/UCA?lang=en;alternate=blanked;strength=primary") returns true().
The expression fn:starts-with ( "-abcdefghi", "-abc",
"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.