Usage of integers as hash keys

Question

Is it appropriate to use integers as keys in a Ruby hash?

Every example from documentation shows a string or symbol being used as a key, but never an integer.

Internally, would integers somehow get converted to strings? I have seen some conflicting information on the subject.

In other words, is there any significant disadvantage to using integer keys to a hash?

Answer 1

Others looking at the answers here might find it interesting to know that an exception happens when you use integers as symbol keys in a Ruby hash {symbol: value}

hash = {1: 'one'} # will not work   hash = {1 => 'one'} # will work 

Requested Explanation:

The simplest answer for why the first example fails is probably that to_sym is not a method that's been implemented for Fixnum integers.

To go more in depth to maybe explaining why that is, one of the main benefits to using symbols is that two symbols are in fact "the same object". Or at least they share the same object ids.

:foo.object_id == :foo.object_id => true 

Strings that are the same do not share the same objects, and therefore do not share the same object ids.

"foo".object_id == "foo".object_id => false 

Like symbols, Fixnum integers that are the same will have the same object ids. Therefore you don't really need to convert them into symbols.

one = 1 => 1 uno = 1 => 1 one.object_id => 3 one.object_id == uno.object_id => true