Should I use quotes or colons for session keys in Ruby on Rails?

Question

Currently I have a session variable that returns the same value when I use both session["test"] or session[:test]. Are these two the same? Is it better to use one over the other?

Thanks

Answer 1

In a standard Ruby Hash they're not the same (string vs symbol)

However, the rails SessionHash subclass calls to_s on the keys before storing them, so all keys are stored as strings (even if you specify a symbol):

class SessionHash < Hash

  def [](key)
    load_for_read!
    super(key.to_s)
  end

  def []=(key, value)
    load_for_write!
    super(key.to_s, value)
  end

That's why session[:test] and session["test"] will return the same value in rails.

Answer 2

No, they aren't precisely the same. They're two ways of accomplishing the same thing.

In general, in Ruby a major use of symbols is as keys. Symbols are :these_things. Hash keys are a typical use for them...

{
  :name => 'Mary',
  :rank => 'Captain'
}

Session keys are also usually symbols.

Using Strings instead won't hurt anything, but symbols are more typical.