Class

Classes in Ruby are first-class objects—each is an instance of class Class.

Typically, you create a new class by using:

class Name
 # some code describing the class behavior
end

When a new class is created, an object of type Class is initialized and assigned to a global constant (Name in this case).

When Name.new is called to create a new object, the new method in Class is run by default. This can be demonstrated by overriding new in Class:

class Class 
 alias old_new new 
 def new (*args)
 print "Creating a new ", self.name, "\n"
 old_new(*args)
 end
end
class Name
end
n = Name.new 

produces:

Creating a new  Name

Classes, modules, and objects are interrelated. In the diagram that follows, the vertical arrows represent inheritance, and the parentheses metaclasses. All metaclasses are instances of the class `Class’.

 +---------+ +-...
 | | |
 BasicObject -----|-->(BasicObject )-------|-...
 ^ | ^ |
 | | | |
 Object ---------|----->(Object )---------|-...
 ^ | ^ |
 | | | |
 +-------+ | +--------+ |
 | | | | | |
 | Module -|---------|--->(Module )-|-...
 | ^ | | ^ |
 | | | | | |
 | Class -|---------|---->(Class )-|-...
 | ^ | | ^ |
 | +---+ | +----+
 | |
obj--->OtherClass---------->(OtherClass)-----------...

Extends any Class to include json_creatable? method.

Related methods