How do methods use hash arguments in Ruby?

Question

I saw hash arguments used in some library methods as I\'ve been learning.

E.g.,

list.search(:titles, genre: \'jazz\', duration_less_than: 270)
         


        

Answer 1

Since Ruby 2.0 you can use keyword arguments ^[1][2] as opposed to the single Hash parameter.

def foo(keyword_arg: 'bar')
  keyword_arg
end

And here's how it behaves.

> foo
=> "bar"
> foo(keyword_arg: 'baz')
=> "baz"

1. http://robots.thoughtbot.com/ruby-2-keyword-arguments
2. http://brainspec.com/blog/2012/10/08/keyword-arguments-ruby-2-0/