I'm getting this error when trying to use include MyModule "Uninitialized constant"
Here is my implementation:

a.rb

class A
  include MyModule

  puts ARRAY
end

my_module.rb

module MyModule
  ARRAY = [1,2,3]
end

CodePudding user response：

Ruby doesn't know about MyModule because it doesn't read my_module.rb

Add at the top of a.rb

require_relative 'my_module'

if these files are in the same folder (or correct path to the file if not)