Calling a method without an explicit receiver in the main environment

Question

When I do:

def hello(*args)
  "Hello " + args.join(' ')
end

send( :hello, "gentle", "readers")  #=> "Hello gentle readers"

is send called on something? I get:

method(:hello).owner #=> Object

Is it called on the Object class or its instance?

Answer 1

Your method:

send( :hello, "gentle", "readers")  #=> "Hello gentle readers"

is the same as:

self.send( :hello, "gentle", "readers")  #=> "Hello gentle readers"

where self in this case is defined as main which is the built-in top-level object.

---

This line of code:

p method(:hello).owner #=> Object

returns Object because you've defined the method :hello at the top-level which means it gets put into the class Object.

Answer 2

Method call without explicit receiver:

send( :hello, "gentle", "readers")

assumes an implicit self as the receiver, which is the main object in this case.

Method definition in the main environment:

def hello(*args)
  "Hello " + args.join(' ')
end

assumes it is defined as an instance method on Object.

Since main is an instance of the Object class, the method definition and the call work together.