Private and self

Ruby
1

Why doesn´t the call with self doesn´t work ? I know that private means
private to the object, but the private methode call is within the same
object (at least it´s what i think). Doesn´t self mean “the object
himself” ? So why is this error occuring ?

test.rb:14:in with_self': private methodprivate_methode’ called for
#PrivateTest:0x2aaaaab00508 (NoMethodError)

class PrivateTest

def private_methode()
puts("I am private")
end

def without_self()
puts("without self")
private_methode()
end

def with_self()
puts("with self")
self.private_methode()
end

private :private_methode
end

test = PrivateTest.new
test.without_self()
test.with_self()
2

On 8/20/06, Marinho T. [email protected] wrote:

Why doesn´t the call with self doesn´t work ? I know that private means
private to the object, but the private methode call is within the same
object (at least it´s what i think). Doesn´t self mean “the object
himself” ? So why is this error occuring ?

>

Just quoting from the Pixcake (or was it Pickaxe :wink: book
[…]

  • Private methods cannot be called with an explicit receiver.
    Because you cannot specify an object when using them, private methods
    can be
    called only in the defining class and by direct descendents within
    that same
    object.

The difference between protected'' and private’’ is fairly subtle,
and
is different in Ruby than in most common OO languages. If a method is
protected, it may be called by any instance of the defining class or
its
subclasses
[…]
So in Ruby surprisingly one canot indicate an explicit reveiver to a
private
method. Even if it is self which comes to a surprise at the beginning.
If I understand correctly this might change in Ruby2, and maybe
ritefully so
;).

Cheers
Robert

Deux choses sont infinies : l’univers et la bêtise humaine ; en ce qui
concerne l’univers, je n’en ai pas acquis la certitude absolue.

  • Albert Einstein