Executing function inside a procedure

Question

I have a function like fun_a(a varchar) which returns a number
I execute the function in sql prompt by select fun_a('hello') from dual;
Now i have to execute that function inside a procedure and return the output of the function to a variable like the following
create or replace procedure x is
a number;
vsql varchar2(255);
i varchar2(40):='hello';
begin
vsql :='select fun_a('||i||') from dual';
execute immediate VSQL INTO a;
dbms_output.put_line(a);
end;
I am not getting the output . Please help me in this

Answer 1

Or even:
CREATE OR REPLACE PROCEDURE x
IS
vsql  VARCHAR2(255);
i     VARCHAR2(40) := 'EMP';
i1    VARCHAR2(40) := 'EMPNO';
a     NUMBER := primary_check_fun(i, i1);
BEGIN
dbms_output.put_line(a);
END;or just for fun,
CREATE OR REPLACE PROCEDURE x
IS
vsql  VARCHAR2(255);
i     VARCHAR2(40) := 'EMP';
i1    VARCHAR2(40) := 'EMPNO';
BEGIN
dbms_output.put_line(primary_check_fun(i, i1));
END;
Well if we're going to extremes Will we could look at it and say that the parameters are pre-defined and just have...
exec dbms_output.put_line(primary_check_fun('EMP','EMPNO'));
;)