In Ruby, is there a difference between %w(x y z) and %w[x y z]?

Question

In Ruby, is there a difference between %w(x y z) and %w[x y z]?

I see both in docs and examples, and both seem to work for me.

Answer 1

The () and [] are called delimiters, and you can use almost any non-alphanumeric character as a delimiter:

%w<x y z>
%w{x y z}
%w~x y z~
%w|x y z|

Some have different opening and closing characters (such as your two examples and my first two examples) and the rest just use the same characters at both ends.

Answer 2

No. All such expressions in ruby support (), [], {}, <>, and any 2 non-word symbols. E.g., these are all valid:

%w/1 2 3/
%w\1 2 3\
%w!1 2 3!
%w.1 2 3.