1  DECLARE
 2     TYPE population_type IS TABLE OF NUMBER INDEX BY VARCHAR2(64);

 3     country_population population_type;
 4     continent_population population_type;
 5     howmany NUMBER;
 6     limit VARCHAR2(64);
 7  BEGIN

 8     country_population('Greenland') := 100000;
 9     country_population('Iceland') := 750000;
10
11     howmany := country_population('Greenland');
12
13     continent_population('Australia') := 30000000;

14
15     continent_population('Antarctica') := 1000; -- Creates new entry
16     continent_population('Antarctica') := 1001; -- Replaces previous value
17
18     limit := continent_population.FIRST;
19     DBMS_OUTPUT.PUT_LINE (limit);
20     DBMS_OUTPUT.PUT_LINE (continent_population(limit));

21
22     limit := continent_population.LAST;
23     DBMS_OUTPUT.PUT_LINE (limit);
24     DBMS_OUTPUT.PUT_LINE (continent_population(limit));
25  END;

Antarctica
1001

Australia
30000000