Assign result of regexp_split_to_array() to Pl/pgSQL array variable

Question

How do I create an array and then put a result of a function into it?
I'm doing it like this:

array text[];
select regexp_split_to_array('whatever this is it splits into array with spaces', E'\\s+')
    into array;

But obviously it doesn't work, when I try to

raise notice '%', array[1];

It's just not how it's done.