Use of :: operator

Rails
1

Hi,

I want to know the use of “::” operator in rails.
Actually, I have created a module with name “Email” and written a method
def check_email(email)
end
I want to access this method. So I went to the “ruby/script console” and
done like as follows:-

“Email::check_email(‘[email protected]’)”
I got an error that “undefined method `check_email’ for Email:Module”.
Can anyone tell me what is wrong with my code?
Also Is it the use of :: operator?

Thanks
Mike

2

Hi,

‘::’ method is used to refer to modules inside a module.

If you define a method inside a module eg)

module Test
def check
puts “check”
end
end

Then you create a module and define an instance method by the name
‘check’
This instance method can only be access by an instance. So it can be
accessed by instances of classes that have included that module only.
You can get the method object directly using
Test.instance_method(:method_name), this will give you the UnboundMethod
obejct which you can then bind to an instance of an object and use it if
you
really needed to, other than that I am not sure if you could do anything
about it directly.

If you want to define a method inside a module and be able to access it
directly using the module without any inclusion & instantiation then you
should do the following:

module Test
def self.check
puts “check”
end
end

Now you can call the method check using Test.check #=> check

On Wed, Apr 28, 2010 at 12:18, Mike D. [email protected] wrote:

I got an error that “undefined method `check_email’ for Email:Module”.
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–

Thanks & Regards,
Dhruva S…

3

Thanks Dhruva.
Now I understood the use of “::” operator.
Thanks
Mike

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