Oracle / PLSQL: IF-THEN-ELSE Statement

SET SERVEROUTPUT ON;

DECLARE
   a number(3) := 100;
   b number(3) := 200;
BEGIN
   IF( a = 100 ) THEN
      IF( b <> 200 ) THEN
         dbms_output.put_line(b);
      END IF;
   END IF;
   dbms_output.put_line(a);
END;

/

Simple PL/SQL Program

SET SERVEROUTPUT ON;

DECLARE
   c_id varchar2(100):= 'AR';
   r_id  varchar2(100);
   c_name varchar2(100);
  BEGIN
   SELECT region_id, country_name INTO r_id, c_name
   FROM countries
   WHERE country_id = c_id;
  dbms_output.put_line('Region Id is: '|| c_id || ' Country Name is: '|| c_name);

END;

/