Difference between `:provider => ' value '` and `provider: 'value'`

Question

To describe a hash for carrierwave configurations, I write like:

{
  provider: 'AWS',
  aws_access_key_id: ENV["aws_access_key_id"],
  aws_secret_access_key: ENV["aws_secret_access_key"],
}

However, tutorials seem the advice to write:

{
  :provider => 'AWS'
  :aws_access_key_id => ENV["aws_access_key_id"],
  :aws_secret_access_key => ENV["aws_secret_access_key"],
}

What is the difference between the two? Is there good reason to use one over the other?

As to your second question, `'a' == "a"` so there is no good reason (with the samples you provide). Please open a new question with proper examples and the error message if you want it answered proper — Nitz, Feb 21 '16 at 18:42
deleted the second questions, I am not sure what it was but its not repeatable. I was thinking as well that 'a' == "a" that got me confused anyway it seems to work now so not sure what caused it. Maybe I was missing hyphen somewhere or my replace all " to ' did not work right for the page. — Kimmo Hintikka, Feb 22 '16 at 09:26

score 3 · Accepted Answer · edited May 23 '17 at 11:50

3

There is no difference.

nitz@comp:~$ irb
irb(main):001:0> {a:1}
=> {:a=>1}

This is a new syntax for specifying hashes with keys that are symbols, which is the "normal" way (as far as I can see) of defining hashes.
Also see What are the benefits of the new hash syntax in Ruby 1.9?

edited May 23 '17 at 11:50

Community

answered Feb 21 '16 at 11:53

Nitz

score 1 · Answer 2 · edited Feb 21 '16 at 12:05

1

The only difference is that you can't do things like dashes with it:

:'foo-moo' => 2

edited Feb 21 '16 at 12:05

mikej

answered Feb 21 '16 at 11:56

antpaw

I'm not sure why you're calling this "'JSON' syntax," considering that in JSON all keys must be double-quoted (`{ foo: 1 }` is not valid JSON; `{ "foo": 1 }` is). – Jordan Running Feb 21 '16 at 19:23

score 1 · Answer 3 · answered Feb 21 '16 at 12:01

1

It's the new syntax for ruby 1.9+, just a syntactic sugar, that's all.

I prefer to use the new as older syntax might get deprecated in near future.

answered Feb 21 '16 at 12:01

Albert Paul

1

The "old" syntax is definitely not going to get deprecated as it is still required if you use anything else than a Symbol as the key. For strings, integers or any other objects, you still need the "old" syntax. In fact, the serialization of `Hash#to_s` uses the "old" syntax only. – Holger Just Feb 21 '16 at 18:00

3 Answers3