Is there a literal notation for an array of symbols?

179
votes

I like this literal expression for an array of strings:

%w( i can easily create arrays of words )

I am wondering if there is a literal to get an array of symbols. I know I can do 

%w( it is less elegant to create arrays of symbols ).map( &:to_sym )

but it would be so wonderful just to use a literal.

2
rubyarrayssymbolssyntactic-sugar
This approach would be nicer than just creating an array of symbols? Or a simple method? Meh. – Dave Newton
in this case, what's even the point to the %w notation ? – m_x
IMO an array of symbols is less cluttered than an array of strings already, and generally less common. YMMV. – Dave Newton
<troll>seems that the ruby team agreed with me since ruby 2...</troll> – m_x
Possible duplicate of Create array of symbols – sjakobi

2 Answers

288
votes

Yes! This is possible now in Ruby 2.0.0. One way to write it is:

%i{foo bar}  # => [:foo, :bar]

You can also use other delimiters, so you could also write %i(foo bar) or %i!foo bar! for example.

This feature was originally announced here:

http://www.ruby-lang.org/zh_TW/news/2012/11/02/ruby-2-0-0-preview1-released/

It is mentioned in the official documentation of Ruby here:

http://ruby-doc.org/core/doc/syntax/literals_rdoc.html#label-Percent+Strings

26
votes

In Ruby 1.x, unfortunately the list of available %-delimiters is limited

Modifier    Meaning
%q[ ]       Non-interpolated String (except for \\ \[ and \])
%Q[ ]       Interpolated String (default)
%r[ ]       Interpolated Regexp (flags can appear after the closing delimiter)
%s[ ]       Non-interpolated Symbol
%w[ ]       Non-interpolated Array of words, separated by whitespace
%W[ ]       Interpolated Array of words, separated by whitespace
%x[ ]       Interpolated shell command