Question

Although I’ve been using Ruby 1.9 for a while, I only recently discovered the newer hash syntax that’s now supported:

settings = {
  host: "localhost",
  port: 5984
}

As opposed to:

settings = {
  "host" => "localhost"
}

I like its similarity to JavaScript’s object noation, and looks a bit like JSON, so I’ll probably switch to using it with all my libraries, but I still want to support other users and my own projects which assume the old syntax.

So it really comes down to a fairly simple question of having to test for both symbols and strings. Is there an easy way to do both of these lines as one?

return true if settings["host"] and settings["db"]

return true if settings[:host] and settings[:db]

Answer 1

Even in Ruby < 1.9, you could use symbols for keys. For example:

# Ruby 1.8.7
settings = { :host => "localhost" }
puts settings[:host] #outputs localhost
settings.keys[0].class # => Symbol

Ruby 1.9 changes the way that you create hashes. It takes the key and converts it to a symbol for you, while eliminating the need for a hash rocket.

# Ruby 1.9.2
settings = { host: "localhost" }
settings[:host] # => "localhost"
settings.keys[0].class # => Symbol

In both cases, if I try to access settings[:name] with settings["name"], I’m going to get nil. All Ruby 1.9 does is allow for a new way of creating hashes. To answer your question, you cannot, as far as I know, use the new {key: value} syntax if you want backwards compatibility with Ruby 1.8.