Blocks in PLSQL Examples

Named Blocks:
----------------

<<FirstBlock>>
DECLARE
 A VARCHAR2(20):='Hello Guys';
 B REAL:=500;
BEGIN
 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER STRING A:= '||A);
 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER REAL B:= '||B);
   DECLARE
    A INTEGER:=400;
    B REAL:=2000;
   BEGIN
    DBMS_OUTPUT.PUT_LINE('THE VALUE OF INNER INTEGER A:= '||A);
    DBMS_OUTPUT.PUT_LINE('THE VALUE OF INNER REAL A:= '||B);
    DBMS_OUTPUT.PUT_LINE('WE R GETTING THE VALUE OF OUTER STRING A FROM INNER BLOCK:= '||FirstBlock.A);
   END;
END;
/

Nested Blocks & Variable Scope:
--------------------------------------------


Ex: 1:-

DECLARE
 V_N1 NUMBER:=&N1;
 V_N2 NUMBER:=&N2;
 V_RES NUMBER:=0;
BEGIN
 DBMS_OUTPUT.PUT_LINE('FIRST NO:= '||V_N1);
 DBMS_OUTPUT.PUT_LINE('SECOND NO:= '||V_N2);
 DBMS_OUTPUT.PUT_LINE('SUM:= '||TO_CHAR(V_N1+V_N2,99999.99));
 DBMS_OUTPUT.PUT_LINE(V_RES);
   DECLARE
    V_SUM NUMBER:=V_N1+V_N2;
    --V_RES:=V_SUM;
    V_RES NUMBER:=V_SUM;
   BEGIN
    DBMS_OUTPUT.PUT_LINE(V_RES);
   END;
  DBMS_OUTPUT.PUT_LINE(V_RES);
END;
/

Ex: 2:-

DECLARE

 A VARCHAR2(20):='Hello Guys';

 B REAL:=0;

BEGIN

 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER STRING A:= '||A);

 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER REAL B:= '||B);

   DECLARE

    A INTEGER:=405;

    B REAL:=2000;

   BEGIN

    DBMS_OUTPUT.PUT_LINE('THE VALUE OF INNER INTEGER A:= '||A);  

    DBMS_OUTPUT.PUT_LINE('THE VALUE OF INNER REAL A:= '||B);

   END;

   DECLARE

    D REAL:=300;

    B VARCHAR2(20):='HELLO GILS';

   BEGIN

     DBMS_OUTPUT.PUT_LINE('THE VALUE OF INNER REAL D:= '||D);  

     DBMS_OUTPUT.PUT_LINE('THE VALUE OF LAST STRING B:= '||B);

   END;

 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER STRING A:= '||A);

 DBMS_OUTPUT.PUT_LINE('THE VALUE OF OUTER REAL B:= '||B);

END;

/

Ur's

AmarAlam