Regarding Constants

Hi,

I am having some difficulty in the use of constants in Ruby. I've a
module:

eg.

···

-------------------
Module Constants

MY_CONST = "hello"

end
-------------------

I include this module in my model. Further, the name of the constant
(MY_CONST) would be passed in a variable say 'var'. My question, is how
do I access the value of the constant from the constant name in 'var'?

Something like, :: + "{#var}" or similar? Any help greatly appreciated.
Thanks.

Regards,
Harnish
--
Posted via http://www.ruby-forum.com/.

Hi,

I am having some difficulty in the use of constants in Ruby. I've a
module:

eg.
-------------------
Module Constants

Use lowercase "m"

I include this module in my model. Further, the name of the constant
(MY_CONST) would be passed in a variable say 'var'. My question, is how
do I access the value of the constant from the constant name in 'var'?

module Constants
GRR="burr!"
end

class Bs
   include Constants

   def self.get_constant(name)
        self.const_get(name.to_sym)
   end
end

p Bs.get_constant("GRR")

Why do you need to access constants this way?

···

On Jul 24, 1:21 pm, Harnish Botadra <harnish_...@yahoo.com> wrote:

If I understand you correctly then:

Module Constants
    MY_CONST = "hello"
end

def get_constant_value_by_name(var)
   Constants.const_get(var)
end

get_constant_value_by_name("MY_CONST")
=> "hello"

Hope this helps,
FireAphis

···

On Jul 24, 11:21 pm, Harnish Botadra <harnish_...@yahoo.com> wrote:

Hi,

I am having some difficulty in the use of constants in Ruby. I've a
module:

eg.
-------------------
Module Constants

MY_CONST = "hello"

end
-------------------

I include this module in my model. Further, the name of the constant
(MY_CONST) would be passed in a variable say 'var'. My question, is how
do I access the value of the constant from the constant name in 'var'?

Something like, :: + "{#var}" or similar? Any help greatly appreciated.
Thanks.

Regards,
Harnish
--
Posted viahttp://www.ruby-forum.com/.

Of course, as Skye pointed out, Module should be lowercase.
Yaniv

···

On Jul 25, 10:17 am, "FireAp...@gmail.com" <FireAp...@gmail.com> wrote:

On Jul 24, 11:21 pm, Harnish Botadra <harnish_...@yahoo.com> wrote:

> Hi,

> I am having some difficulty in the use of constants in Ruby. I've a
> module:

> eg.
> -------------------
> Module Constants

> MY_CONST = "hello"

> end
> -------------------

> I include this module in my model. Further, the name of the constant
> (MY_CONST) would be passed in a variable say 'var'. My question, is how
> do I access the value of the constant from the constant name in 'var'?

> Something like, :: + "{#var}" or similar? Any help greatly appreciated.
> Thanks.

> Regards,
> Harnish
> --
> Posted viahttp://www.ruby-forum.com/.

If I understand you correctly then:

Module Constants
    MY_CONST = "hello"
end

def get_constant_value_by_name(var)
   Constants.const_get(var)
end

get_constant_value_by_name("MY_CONST")
=> "hello"

Hope this helps,
FireAphis

Of course, as Skye pointed out Module should be lowercase.
You can see that there's a slight difference between my and Skye's
implementation. That's because 'const_get' can receive either a symbol
or a string. I am personally not familiar with to_sym method. But if I
want to pass a symbol instead of a string I'd use 'var.intern'. That
is
    Constants.const_get(var.intern)
which is exactly the same as
    Constants.const_get(var)

FireAphis

···

On Jul 25, 10:17 am, "FireAp...@gmail.com" <FireAp...@gmail.com> wrote:

On Jul 24, 11:21 pm, Harnish Botadra <harnish_...@yahoo.com> wrote:

> Hi,

> I am having some difficulty in the use of constants in Ruby. I've a
> module:

> eg.
> -------------------
> Module Constants

> MY_CONST = "hello"

> end
> -------------------

> I include this module in my model. Further, the name of the constant
> (MY_CONST) would be passed in a variable say 'var'. My question, is how
> do I access the value of the constant from the constant name in 'var'?

> Something like, :: + "{#var}" or similar? Any help greatly appreciated.
> Thanks.

> Regards,
> Harnish
> --
> Posted viahttp://www.ruby-forum.com/.

If I understand you correctly then:

Module Constants
    MY_CONST = "hello"
end

def get_constant_value_by_name(var)
   Constants.const_get(var)
end

get_constant_value_by_name("MY_CONST")
=> "hello"

Hope this helps,
FireAphis