Ruby class types and case statements

Question

What is the difference between

case item.class
when MyClass
  # do something here
when Array
  # do something different here
when String
  # do a third thing         


        

Answer 1

In Ruby, a class name is a constant that refers to an object of type Class that describes a particular class. That means that saying MyClass in Ruby is equivalent to saying MyClass.class in Java.

obj.class is an object of type Class describing the class of obj. If obj.class is MyClass, then obj was created using MyClass.new (roughly speaking). MyClass is an object of type Class that describes any object created using MyClass.new.

MyClass.class is the class of the MyClass object (it's the class of the object of type Class that describes any object created using MyClass.new). In other words, MyClass.class == Class.