A VARCHAR2 is not the same as an array (collection or PL/SQL table), and cannot be indexed as such. You need to use Oracle's String functions. Here is an example to print out each character of each varchar2 array element:
CREATE OR REPLACE PROCEDURE Proc_Array(
param_Array IN pkg_glb_variables.val_Array
)
IS
vElement VARCHAR2(3000);
vLength PLS_INTEGER;
BEGIN
for i in 1 .. param_Array.count
loop
DBMS_OUTPUT.put_line('aRRay('||i||') :'||param_Array(i));
vElement := param_array(i);
vLength := length(vElement);
for i_2 in 1 .. vLength
loop
DBMS_OUTPUT.put_line('aRRay('||i_2||') :'||
substr(vElement,i_2,1) );
end loop;
end loop;
END;
A test to call the procedure:
declare
a pkg_glb_variables.val_Array;
begin
a(1) := 'HELLO';
a(2) := 'goodbye';
proc_array ( a );
end;
The resulting dbms_output:
my output - aRRay(1) :HELLO
my output - aRRay(1) :H
my output - aRRay(2) :E
my output - aRRay(3) :L
my output - aRRay(4) :L
my output - aRRay(5) :O
my output - aRRay(2) :goodbye
my output - aRRay(1) :g
my output - aRRay(2) :o
my output - aRRay(3) :o
my output - aRRay(4) :d
my output - aRRay(5) :b
my output - aRRay(6) :y
my output - aRRay(7) :e