array agg - PostgreSQL array_agg order

Question

Table 'animals':

animal_name animal_type
Tom         Cat
Jerry       Mouse
Kermit      Frog

Query:

SELECT 
array_to_string(array_agg(animal_name),';') animal_names,
array_to_string(array_agg(animal_type),';') animal_types
FROM animals;

Expected result:

Tom;Jerry;Kerimt, Cat;Mouse;Frog
OR
Tom;Kerimt;Jerry, Cat;Frog;Mouse

Can I be sure that order in first aggregate function will always be the same as in second. I mean I would't like to get:

Tom;Jerry;Kermit, Frog;Mouse,Cat

Answer 1

Use an ORDER BY, like this example from the manual:

SELECT array_agg(a ORDER BY b DESC) FROM table;