How do I dynamically invoke or call a class in Rails?

Question

Assuming I can construct a string that matches an existing class, how do I invoke it?

For example, I have several classes:

• MyClass1
• MyClass2
• MyClass3

And I want to dynamically invoke each of them by constructing a string that matches their names. If they all had the method "methods", how do I do something like this?:

(1..3).each do |n|
  ("MyClass"+n).methods
end

Answer 1

constantize fits the bill. You can read more about it here. In your case it would be something like:

(1..3).each do |n|
  "MyClass#{n}".constantize.methods
end