how to create associative array in plsql code example

Example: associative array in pl sql

DECLARE
    -- declare an associative array type
    TYPE t_capital_type 
        IS TABLE OF VARCHAR2(100) 
        INDEX BY VARCHAR2(50);
    -- declare a variable of the t_capital_type
    t_capital t_capital_type;
    -- local variable
    l_country VARCHAR2(50);
BEGIN
    
    t_capital('USA')            := 'Washington, D.C.';
    t_capital('United Kingdom') := 'London';
    t_capital('Japan')          := 'Tokyo';
    
    l_country := t_capital.FIRST;
    
    WHILE l_country IS NOT NULL LOOP
        dbms_output.put_line('The capital of ' || 
            l_country || 
            ' is ' || 
            t_capital(l_country));
        l_country := t_capital.NEXT(l_country);
    END LOOP;
END;
/