Associative Array and it's collection Methods

CREATE OR REPLACE PROCEDURE xx_AssocArr
AS

TYPE xx_AsscArr IS TABLE OF VARCHAR2(20)
INDEX BY PLS_INTEGER;

TYPE xx_AsscArr1 IS TABLE OF NUMBER
INDEX BY PLS_INTEGER;

TYPE xx_AsscArr2 IS TABLE OF VARCHAR2(40)
INDEX BY VARCHAR2(20);

TYPE xx_AsscArr3 IS TABLE OF NUMBER
INDEX BY VARCHAR2(20);

V1 xx_AsscArr;

V2 xx_AsscArr1;

V3 xx_AsscArr2;

V4 xx_AsscArr3;

i NUMBER;
J NUMBER;
z VARCHAR2(30);

BEGIN

dbms_output.put_line('Hi..');

/*Like in VARRAY and NESTED TABLE 
associative array doesn't require 
initialization directly values
can be assigned*/

--These are also called as key-value pairs

--v1 has values of string type and indexed by integer

v1(1000):='Vizag';

v1(1500):='Hyderabad';

v1(-100):='Atlanta';

dbms_output.put_line('FIRST INDEX of V1 : '||v1.FIRST);
dbms_output.put_line('LAST INDEX of V1 : '||v1.LAST);
dbms_output.put_line('count of V1 : '||v1.COUNT);

IF (v1.EXISTS(-100)) THEN
   dbms_output.put_line('Element exists at index -100 : '|| v1(-100));
ELSE
   dbms_output.put_line('Element does not exist');
END IF;

dbms_output.put_line('Index prior to element at 1000 : '||v1.PRIOR(1000));

dbms_output.put_line('Index next to element at 1000 : '||v1.NEXT(1000));

dbms_output.put_line('Printing V1');

j:=v1.FIRST;

WHILE j is NOT NULL LOOP
dbms_output.put_line('Element at index # '||j||' '||v1(j));
        j:=v1.NEXT(j);
END LOOP;

v1.DELETE(1000);

dbms_output.put_line('Printing V1');

j:=v1.FIRST;

WHILE j is NOT NULL LOOP
dbms_output.put_line('Element at index # '||j||' '||v1(j));
        j:=v1.NEXT(j);
END LOOP;

dbms_output.put_line('Working on V3');

/*v3 has values of string and indexed by strings!!
*/

v3('vizag'):='This is vizag city';

v3('pune'):='This is pune city';

v3('banglore'):='This is blore city';

dbms_output.put_line('Printing V3');

z:=v3.FIRST;

WHILE z is NOT NULL LOOP
dbms_output.put_line('Element at index # '||z||' '||v3(z));
        z:=v3.NEXT(z);
END LOOP;

v3.DELETE('pune');

dbms_output.put_line('Printing V3');

z:=v3.FIRST;

WHILE z is NOT NULL LOOP
dbms_output.put_line('Element at index # '||z||' '||v3(z));
        z:=v3.NEXT(z);
END LOOP;


EXCEPTION

WHEN OTHERS THEN

dbms_output.put_line('Error is : '||SQLERRM);

END xx_AssocArr;
/