Dynamically access class constants?

ruby-talk
1

I've been looking for a method similar to:

Obj.send(:method)

but to access class constants. So if I have:

class MyObj
  MY_CONSTANT_1
end

I want to access MyObj::MY_CONSTANT_1 by using a variable like foo =
MY_CONSTANT_1 and then MyObj::send(:foo), but obviously send is only
meant to work with methods and not constants.

Is there any way to do this? I've looked but am having difficulty
finding anything.

Thanks,
Marli

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2

Marli Ba wrote:

I've been looking for a method similar to:

Obj.send(:method)

but to access class constants. So if I have:

class MyObj
  MY_CONSTANT_1
end

I want to access MyObj::MY_CONSTANT_1 by using a variable like foo =
MY_CONSTANT_1 and then MyObj::send(:foo), but obviously send is only
meant to work with methods and not constants.

Is there any way to do this? I've looked but am having difficulty
finding anything.

Thanks,
Marli
  
I am slightly confused by your example, but you definitely need Module#const_get: class Module - RDoc Documentation

irb(main):001:0> class A
irb(main):002:1> B = 1
irb(main):003:1> end
=> 1
irb(main):004:0> A.const_get(:B)
=> 1

-Justin

3

class MyObj
  MY_CONSTANT_1 = "hello"
end

=> "hello"

c = "MY_CONSTANT_1"

=> "MY_CONSTANT_1"

MyObj.const_get(c)

=> "hello"

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4

Justin Collins wrote:

I am slightly confused by your example, but you definitely need
Module#const_get:
class Module - RDoc Documentation

irb(main):001:0> class A
irb(main):002:1> B = 1
irb(main):003:1> end
=> 1
irb(main):004:0> A.const_get(:B)
=> 1

-Justin

Ah, sorry for the confusion. const_get is exactly what I was looking
for though, thanks!

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