# Check if a parameter is a constant or an object?

**URL:** <https://www.ruby-forum.com/t/check-if-a-parameter-is-a-constant-or-an-object/118733>\
**Category:** Ruby\
**Created:** [October 30, 2007, 2:10pm UTC](https://www.ruby-forum.com/t/check-if-a-parameter-is-a-constant-or-an-object/118733 "2007-10-30T14:10:31Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\
**Post date:** [October 30, 2007, 2:10pm UTC](https://www.ruby-forum.com/t/check-if-a-parameter-is-a-constant-or-an-object/118733/1 "2007-10-30T14:10:31Z")

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Hi all

def some\_method(arg)

# How do I check here if arg is a constant or an object?

end

Thanks 🙂  
Josh

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**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\
**Post date:** [October 30, 2007, 6:02pm UTC](https://www.ruby-forum.com/t/check-if-a-parameter-is-a-constant-or-an-object/118733/2 "2007-10-30T18:02:31Z")

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arg.is\_a?(Class) || arg.is\_a?(Module) ? “class/module” :  
“object/number/whatever”

2007/10/30, Joshua M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

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**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\
**Post date:** [October 30, 2007, 6:08pm UTC](https://www.ruby-forum.com/t/check-if-a-parameter-is-a-constant-or-an-object/118733/3 "2007-10-30T18:08:57Z")

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Hi –

On Tue, 30 Oct 2007, Joshua M. wrote:

> Hi all
> 
> def some\_method(arg)
> 
> # How do I check here if arg is a constant or an object?
> 
> end

Constants are bound to objects:

X = “hi”  
some\_method(X)

The method just receives an object reference. It doesn’t actually  
receive a constant; the constant is just an identifier.

(Or am I misunderstanding?)

David