What is the %w “thing” in ruby?

Question

I\'m referring to the %w operator/constructor/whatever you may call it, used like this:

%w{ foo bar baz }
=> [\"foo\", \"bar\", \"baz\"]

Answer 1

• What is the proper name of that %w "thing"? Operator? Literal? Constructor?

Not actually sure, string encoded literals I guess.

• Does it matter whether I use {}s instead of []s?

Nope. You can use almost any character actually. If you start with a {, [ or ( you need to close with the closing counterpart of that character, but other characters are closed with the same character. You probably want to use a character that is not going to appear inside your literal.

%w_ foo bar _

• Are there any other things like this (for example, one that gives you an array of symbols instead)?

Not one for an array of symbols, but there is a %q for a single quoted string, %Q for a double quoted string, %r for a regex, and probably a few other as well I am forgetting.

• Can they be "nested" (one %w inside another %w, in order to create nested arrays)?

Nope. They are for quick and easy ways to create simple objects. If you need nesting, you need to use the more verbose syntax.