Omitting the RETURN statement in a function in PL/SQL V1 does not cause a problem at runtime. However, in versions after V1, this will cause a runtime error.
To preserve V1 behavior, the PL/SQL conversion utility adds a RETURN statement with a NULL argument to functions that are missing a RETURN statement.
Note: A missing RETURN statement in a function will not generate a compiler error, but it will generate a runtime error in versions after V1.
The conversion utility converts this PL/SQL V1 code:
FUNCTION noreturn (arg IN NUMBER) RETURN char IS
BEGIN
IF (arg > 100000) THEN
TEXT_IO.PUT_LINE ('The point of no return.');
ENDIF;
RETURN statement is missing
END;
. . . to this:
FUNCTION noreturn (arg IN NUMBER) RETURN char IS
BEGIN
IF (arg > 100000) THEN
TEXT_IO.PUT_LINE ('The point of no return.');
ENDIF;
RETURN NULL; RETURN NULL added by converter
END;