Ruby: what does %w(array) mean?

Question

I'm looking at the documentation for FileUtils. I'm confused by the following line:

FileUtils.cp %w(cgi.rb complex.rb date.rb), '/usr/lib/ruby/1.6'

What does the %w mean? Can you point me to the documentation?

Answer 1

%w(foo bar) is a shortcut for ["foo", "bar"]. Meaning it's a notation to write an array of strings seperated by spaces instead of commas and without quotes around them. You can find a list of ways of writing literals in zenspider's quickref.

Answer 2

%W (and %w) allow you to create an Array of strings without using quotes and commas.

Answer 3

I think of %w() as a "word array" - the elements are delimited by spaces.

There are other % things:

• %r() is another way to write a regular expression.
• %q() is another way to write a single-quoted string (and can be multi-line, which is useful)
• %Q() gives a double-quoted string
• %x() is a shell command

I don't know any others, but there may be some lurking around in there...