Arrays in PL/pgSQL routines?

Can arrays be declared in PL/pgSQL routines?  If so, how?

Section 8.10 of the documentation (http://www.postgresql.org/docs/7.4/static/arrays.html) tells how to declare and use arrays as table columns.  But I don’t find any part of the documentation that says how to declare a simple array local to a PL/pgSQL function.  I tried the following guess, but it only won me a “syntax error at or near VARCHAR:

DECLARE

  my_array VARCHAR [];

  …

~ TIA

~ Ken