Hi,
I tried running the below inline function in SQL Developer
with function calculator (m number, r number) return number
is begin
return m * r;
end calculator;
select calculator(3, 2) as calc from dual;
But throws below error

SQL Developer version : Version 3.2.20.09
Oracle Data base : 12c
Please note , when I run from SQLPlus I am getting the intended output
Regards,
Shamed H