%Q, %q, %W, %w, %x, %r, %s

%Q | %q | %W | %w | %x | %r | %s

 
%Q
This is an alternative for double-quoted strings, when you have more quote characters in a string.Instead of putting backslashes in front of them, you can easily write:

>> %Q(Joe said: "Frank said: "#{what_frank_said}"")
=> "Joe said: "Frank said: "Hello!"""

The parenthesis “()” can be replaced with any other non-alphanumeric characters and non-printing characters (pairs), so the following commands are equivalent:

>> %Q!Joe said: "Frank said: "#{what_frank_said}""!
>> %Q[Joe said: "Frank said: "#{what_frank_said}""]
>> %Q+Joe said: "Frank said: "#{what_frank_said}""+

You can use also:

>> %/Joe said: "Frank said: "#{what_frank_said}""/
=> "Joe said: "Frank said: "Hello!"""


%q
Used for single-quoted strings.The syntax is similar to %Q, but single-quoted strings are not subject to expression substitution or escape sequences.

>> %q(Joe said: 'Frank said: '#{what_frank_said} ' ')
=> "Joe said: 'Frank said: '\#{what_frank_said} ' '"

 
%W
Used for double-quoted array elements.The syntax is similar to %Q

>> %W(#{foo} Bar Bar\ with\ space)
=> ["Foo", "Bar", "Bar with space"]

 
%w
Used for single-quoted array elements.The syntax is similar to %Q, but single-quoted elements are not subject to expression substitution or escape sequences.

>> %w(#{foo} Bar Bar\ with\ space)
=> ["\#{foo}", "Bar", "Bar with space"]

 
%x
Uses the ` method and returns the standard output of running the command in a subshell.The syntax is similar to %Q.

>> %x(echo foo:#{foo})
=> "foo:Foo\n"

 
%r
Used for regular expressions.The syntax is similar to %Q.

>> %r(/home/#{foo})
=> "/\\/home\\/Foo/"

 
%s
Used for symbols.It’s not subject to expression substitution or escape sequences.

>> %s(foo)
=> :foo

>> %s(foo bar)
=> :"foo bar"

>> %s(#{foo} bar)
=> :"\#{foo} bar"
Advertisements

19 thoughts on “%Q, %q, %W, %w, %x, %r, %s

  1. Pingback: %Q, %q, %W, %w, %x, %r, %s | myrubylearning

  2. Reblogged this on and commented:
    I stumbled across this and found it rather informative. Obviously I knew of some of these, such as %Q, but certainly never knew of the differences between them all. And the fact that you can use any non alphanumeric chars for the parenthesis is ‘pleasurable’ ^_^

  3. Pingback: Introduction to Calabash, Level 2 – testingtofail

  4. Pingback: Arbitrary quotations | Skila

  5. Pingback: More Ruby Miscellanea | Et Cetera

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s