Question

Why in below code snippet foo replaces its definition?

def foo
  def foo
    1
  end
end

---

for the first time foo is nil

foo
=> nil

foo.foo
=> 1

Now if I call foo again:

foo
=> 1

As you can see foo is not nil anymore. Can some one explain this to me? thanks.

Answer 1

def foo
  p "about to redef foo"
  def foo
    1
  end
end

foo
"about to redef foo"
=> nil
foo
=> 1

Also, when you call foo.foo, it seems like you’re trying to access the inner foo method, but it doesn’t work that way. Your foo method is actually defined on Object, so you’re actually calling 1.foo.