Code & Clay Notes to self. Mainly Ruby/Rails.

Use is_a? when checking class

Do not use == when checking that an object is of a given class.

Whilst it works here:

> Array.new.class == Array
=> true

…it won’t work with descendants of the class we’re checking against:

> class Thing < Array; end
=> nil
> Thing.new.class
=> Thing
> Thing.new.class == Array
=> false

Instead use is_a?:

> Array.new.is_a? Array
=> true
> Thing.new.is_a? Thing
=> true
> Thing.new.is_a? Array
=> true