Creating your own classes

Classes describe the behavior of objects. It is nice to learn that the standard types that come with Crystal are, for the most part, just ordinary classes you could have implemented on your own. Also, your application will need some more specialized classes, so let's create them.

New classes are created with the class keyword, followed by the name and then the definition of the class. The following a minimal example:

class Person
end
person1 = Person.new
person2 = Person.new

This example creates a new class named Person and then two instances of this class – two objects. This class is empty – it doesn't define any method or data, but Crystal classes come with some functionality by default:

p person1        # You can display any object and 
  # inspect it
p person1.to_s   # Any object can be transformed into
  # a String
p person1 == person2 ...