Accessing array elements in a FOR PL/pgsql loop

For each element in the array, I need to make some operation with plpgsql.
I usually use the syntax:

DECLARE
array_len int;
BEGIN
array_len := array_upper(i_array, 1);
FOR i IN 1 .. array_len
LOOP
SOME OPERATION (i_array[i])
END LOOP;

But I don't like that. Is there any built-in way to do that without
using the length, i.e like in python, e.g.
for element in array:
....
This example does not work in Postgres.

I think I need a built-in function to make a column from an array, like
in the backwards operation SELECT ARRAY(column)