# Returning with methods **URL:** \ **Category:** ruby-talk\ **Created:** [16 January 2008 04:14 UTC](https://rubytalk.org/t/returning-with-methods/43805 "2008-01-16T04:14:34Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Ryan\_Lewis](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@Ryan\_Lewis](https://rubytalk.org/u/Ryan_Lewis)\ **Post date:** [16 January 2008 04:14 UTC](https://rubytalk.org/t/returning-with-methods/43805/1 "2008-01-16T04:14:34Z")
struct.rb:   #!/usr/bin/env ruby   class User \< Struct.new(:screenname, :password)     def initialize(sn, pw)       self.screenname = sn       self.password = pw     end     def inspect       self.values     end   end in IRB:   \> irb -r struct.rb   irb(main):001:0\> myusr = User.new "c00lryguy", "pass"   =\> c00lryguypass #Returns as an array as a string   irb(main):002:0\> myusr.values   =\> ["c00lryguy", "pass"] #Returns as an array   irb(main):003:0\> myusr   =\> c00lryguypass #Again, returns as an array as a string Now, why doesn't the inspect method return as an array? > **···** > > -- > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). ---
**Author:** ![Gary\_Wright](https://avatars.discourse-cdn.com/v4/letter/g/58956e/32.png) [@Gary\_Wright](https://rubytalk.org/u/Gary_Wright)\ **Post date:** [16 January 2008 05:43 UTC](https://rubytalk.org/t/returning-with-methods/43805/2 "2008-01-16T05:43:12Z")
It does. Try myusr.inspect.class The problem is that IRB has to write that object to stdout so Array#to\_s gets called on the array returned by inspect. It is probably a bad idea to break the convention that inspect returns a string. Gary Wright > **···** > > On Jan 15, 2008, at 11:14 PM, Ryan Lewis wrote: > > > Now, why doesn't the inspect method return as an array? ---
**Author:** ![Ryan\_Lewis](https://avatars.discourse-cdn.com/v4/letter/r/c4cdca/32.png) [@Ryan\_Lewis](https://rubytalk.org/u/Ryan_Lewis)\ **Post date:** [16 January 2008 06:02 UTC](https://rubytalk.org/t/returning-with-methods/43805/3 "2008-01-16T06:02:00Z")
Gary Wright wrote: > It does. Try > > myusr.inspect.class > > The problem is that IRB has to write that object to stdout so > Array#to\_s gets called on the array returned by inspect. > > It is probably a bad idea to break the convention that inspect > returns a string. > > Gary Wright Well, what I'm basically trying to figure out is how to change the a class into another class. Heres my new struct.rb:   #!/usr/bin/env ruby   class Hash      def to\_struct(struct\_name)         Struct.new(struct\_name,\*keys).new(\*values)      end    end   class User     def initialize(sn, pw, dob)       vars = {:screenname =\> sn,               :password =\> pw,               :dob =\> Time.parse(dob),               :join\_date =\> Time.now,               :age =\> Time.now.year - Time.parse(dob).year}       return vars.to\_struct("User")     end   end Now when I call User.new, I want it to turn the User class into the 'vars' Structure > **···** > > -- > Posted via [http://www.ruby-forum.com/\](http://www.ruby-forum.com/%5C). ---
**Author:** ![Stefano\_Crocco](https://avatars.discourse-cdn.com/v4/letter/s/5f9b8f/32.png) [@Stefano\_Crocco](https://rubytalk.org/u/Stefano_Crocco)\ **Post date:** [16 January 2008 08:45 UTC](https://rubytalk.org/t/returning-with-methods/43805/4 "2008-01-16T08:45:44Z")
> Well, what I'm basically trying to figure out is how to change the a > class into another class. Heres my new struct.rb: >   #!/usr/bin/env ruby >   class Hash >      def to\_struct(struct\_name) >         Struct.new(struct\_name,\*keys).new(\*values) >      end >    end > >   class User >     def initialize(sn, pw, dob) >       vars = {:screenname =\> sn, > >               :password =\> pw, >               :dob =\> Time.parse(dob), >               :join\_date =\> Time.now, >               :age =\> Time.now.year - Time.parse(dob).year} > >       return vars.to\_struct("User") >     end >   end > > Now when I call User.new, I want it to turn the User class into the > 'vars' Structure I'm not sure whether your approach will do what you want (if I understand you correctly), for several reasons: 1) your to\_struct method will attempt to create a new class called struct\_name every time it is called. This will produce a warning about redefining a constant if it is called more than once with the same parameter. 2) the to\_struct method will return an instance of class Struct::User (the name of the class is struct\_name), which is just another class, only with the method added. 3) the return value of the initialize method is always ignored. If you wanted User.new to return the value returned by User#initialize, you need to redefine User.new. If you do, though, you won't be able to access the new user object. Look at this: class C   def C.new(var)     obj = allocate     return obj.send(:initialize, var) #initialize is private   end   def initialize var     @var = var     @var \* 2   end end c = C.new(3) puts c =\> 6 Now, you have no variable containing the instance of C you just created. I think you can use an OpenStruct instead of a Struct. OpenStruct is like a hash, but you can access items using method notation. Since OpenStruct can be initialized with a hash, you can define your to\_struct method like this: require 'ostruct' class Hash   def to\_struct     OpenStruct.new self   end end If you truly need to use a Struct, you should first check whether a class with that name is already defined, and create it only if it isn't. For instance: class Hash   def to\_struct name     cls = Struct.const\_get(name) rescue Struct.new( name, \*keys)     cls.new \*values   end end I hope this helps Stefano