Question

Please, do not attack. Here’s the example and code that made me think about this.

I’m studying ruby on rails and am in the midst of the MVC and params[] operator. And have been laying down some proofs or something, reminders on the inside cover of my notebook dedicated to rails, anyway

"So we don't just want to call tweet #1. Tweet.find(1) isn't enough."
===> we need Tweet.find(params[:id])

params[:id] aka params = { :id => 1 }

So I was labeling the different parts to my self, starting with the hash. “The 1 is the value, the :id is the key, the “params” is the….pointer?

Is params a pointer? Is it a variable?

EDIT: Are there any other “variables” (for a lack of a better term) that accept :keys without values other than params? Is this a special type of “container” or is it normal to just accept :keys without values
EDIT2: Are all variables technically pointers? If this true, are :keys inside of hashes technically pointers as well? Haha if this is true params is a pointer pointing to a pointer, which sounds about right.

Answer 1

I don’t think you’re using the right terms here. Maybe this will help:

• The params token is a variable name that holds a reference to some object.
• Technically, params is a method that returns a reference to a Hash object.
• In practice, you treat params as a hash because params.is_a?(Hash) == true.
• The :id token is a Symbol object.
• In params[:id] the :id is the key for a hash value.

IMHO, it’s generally not useful to think of objects in Ruby as pointers–unless you’re deliberately using them that way for some reason. But yes, under the hood there are a lot of layers of indirection that turn C pointers into Ruby objects at runtime.