Convert string to class name without using eval in ruby?

Question

I have something like this:

string = "Post"

I would like to convert the string to a class name literal. I use eval like this to convert the string:

eval(string) #=> Post

Being a javaScript developer I try to avoid eval. Is there a better way of doing this in Ruby? Or is using eval the preferred way of handling this?

Plain ruby. I am aware that Ruby on Rails has a method for this stackoverflow.com/questions/3464007/… — Stratus3D
– Stratus3D, Commented May 13, 2014 at 17:00
@EdgarOrtega not a duplicate. That question is for RoR. This question is for just Ruby. — Stratus3D
– Stratus3D, Commented Oct 29, 2019 at 17:25

MxLDevs · Accepted Answer · 2014-05-13 16:59:26Z

34

You can try

class Post
end

Object.const_get("Post")

Which returns the Post class

answered May 13, 2014 at 16:59

MxLDevs

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Comments

Brian Samson · Accepted Answer · 2014-05-13 17:02:37Z

26

string = "Fixnum"
clazz = Object.const_get(string)
clazz.name # => "Fixnum"

If you are in a rails context, you can also use the `#constantize method on string

clazz = string.constantize # => Fixnum

answered May 13, 2014 at 17:02

Brian Samson

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constantize is best than others