# Issue related to class initialization and irb **URL:** \ **Category:** Ruby\ **Created:** [June 29, 2007, 6:45pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174 "2007-06-29T18:45:52Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 6:45pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/1 "2007-06-29T18:45:52Z")
Hello all, My class is a library that allows users to read information/tags etc from Flac files. When the class is initialized in irb the content of every single instance variable is dumped to the console. This library parses a lot of data from various blocks, and has many data structures to hold it all. As such, this output can contain as much as two screens worth. Some of this data is non-readable and is for ‘top-secret internal use only’. That is, it isn’t secret, but it has no value or use to the user directly ;). Anyway, I would really like to clean up this output and have irb print only eg: =\> #FlacInfo:0x6f97cca4 Or perhaps the above with a brief enumeration of the blocks found and their sizes and/or offsets. To this end I tried defining the class’ to\_s method, and modifying the initialize method’s return value. Neither had an effect. How might I accomplish this? Thanks for consideration, -d ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 6:57pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/2 "2007-06-29T18:57:54Z")
Alle venerdì 29 giugno 2007, darren kirby ha scritto: > secret, but it has no value or use to the user directly ;). > > Thanks for consideration, > -d I think you should redefine the inspect method: irb: 006\> class C irb: 007+\> def initialize x irb: 008+\> @x = x irb: 009+\> end irb: 010+\> def inspect irb: 011+\> “C: x=#{@x}” irb: 012+\> end irb: 013+\> end irb: 015\> C.new 2 =\> C: x2 I hope this helps Stefano ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:01pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/3 "2007-06-29T19:01:54Z")
On Jun 29, 10:44 am, darren kirby [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > secret, but it has no value or use to the user directly ;). > > ## Thanks for consideration, -d > > darren kirby :: Part of the problem since 1976 ::[http://badcomputer.org](http://badcomputer.org) > “…the number of UNIX installations has grown to 10, with more expected…” > > - Dennis Ritchie and Ken Thompson, June 1972 What you want to do is redefine the inspect method. irb(main):001:0\> class Test irb(main):002:1\> attr\_accessor :foo, :bar irb(main):003:1\> end =\> nil irb(main):004:0\> a = Test.new =\> #Test:0x100daec irb(main):005:0\> a.foo = 42 =\> 42 irb(main):006:0\> a.bar = “a place to buy drinks” =\> “a place to buy drinks” irb(main):007:0\> a =\> #\ irb(main):008:0\> class Test irb(main):009:1\> def inspect irb(main):010:2\> “#Test:#{self.object\_id}” irb(main):011:2\> end irb(main):012:1\> end =\> nil irb(main):013:0\> a =\> #Test:8416630 HTH, Chris ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:12pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/4 "2007-06-29T19:12:55Z")
> irb(main):004:0\> a = Test.new > =\> #Test:0x100daec > irb(main):013:0\> a > =\> #Test:8416630 Does anyone know why the value returned by Object#object\_id is different to the value returned by the ‘new’ method? Is one hex and the other is not? ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:07pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/5 "2007-06-29T19:07:54Z")
> =\> #FlacInfo:0x6f97cca4 > Try defining a method called ‘inspect’ instead of ‘to\_s’. I’ll assume > you know how to form the desired string, as I don’t know what methods > are required to do that off the top of my head. ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:20pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/6 "2007-06-29T19:20:55Z")
On Jun 29, 11:11 am, “Dan Stevens (IAmAI)” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > irb(main):004:0\> a = Test.new > > =\> #Test:0x100daec > > irb(main):013:0\> a > > =\> #Test:8416630 > > Does anyone know why the value returned by Object#object\_id is > different to the value returned by the ‘new’ method? Is one hex and > the other is not? Please search the mailing list - I believe this has been discussed twice in the last few weeks. ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:18pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/7 "2007-06-29T19:18:55Z")
First off, thanks to Stefano, Chris, and Dan. inspect was what I was looking for and I have it printing what I would like. quoth the Dan Stevens (IAmAI): > Does anyone know why the value returned by Object#object\_id is > different to the value returned by the ‘new’ method? Is one hex and > the other is not? This is a follow-up question for me as well. Even when the object\_id value is represented in hex it does not match the default output. I guess the default value is the object’s address in memory or somesuch? Looking through ‘Object’, ‘Kernel’, and a few others in the Pickaxe book, I can find no relevant method (which doesn’t mean it isn’t there ;)). Is there a way to get this value? Does it really matter or is it just cosmetic? thanks, -d ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 7:25pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/8 "2007-06-29T19:25:56Z")
On Jun 29, 11:17 am, darren kirby [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > This is a follow-up question for me as well. Even when the object\_id value is > represented in hex it does not match the default output. I guess the default > value is the object’s address in memory or somesuch? The hex value is double the object\_id. So in my example, redefining inspect as “#Test:0x#{(self.object\_id\*2).to\_s(16)}” would give you what you’re expecting. Chris ---
**Author:** ![darren\_kirby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/ed8c4c/32.png) [@darren\_kirby](https://www.ruby-forum.com/u/darren_kirby)\ **Post date:** [June 29, 2007, 11:21pm UTC](https://www.ruby-forum.com/t/issue-related-to-class-initialization-and-irb/108174/9 "2007-06-29T23:21:27Z")
quoth the Chris S.: > would give you what you’re expecting. > > Chris Thanks again Chris. I still have one more issue here. My knowledge of access control is admittedly superficial, but since ‘inspect’ is called internally I should be able to define it as a private method shouldn’t I? Or is it bombing because it is called from irb? ## When I define it privately I get: ## irb(main):016:0\> song = FlacInfo.new(“test.flac”) NoMethodError: private method `inspect' called for # from /usr/lib/ruby/1.8/irb.rb:298:in`output\_value’ from /usr/lib/ruby/1.8/irb.rb:151:in `eval_input' from /usr/lib/ruby/1.8/irb.rb:259:in`signal\_status’ from /usr/lib/ruby/1.8/irb.rb:147:in `eval_input' from /usr/lib/ruby/1.8/irb/ruby-lex.rb:244:in`each\_top\_level\_statement’ from /usr/lib/ruby/1.8/irb/ruby-lex.rb:230:in `loop' from /usr/lib/ruby/1.8/irb/ruby-lex.rb:230:in`each\_top\_level\_statement’ from /usr/lib/ruby/1.8/irb/ruby-lex.rb:229:in `catch' from /usr/lib/ruby/1.8/irb/ruby-lex.rb:229:in`each\_top\_level\_statement’ from /usr/lib/ruby/1.8/irb.rb:146:in `eval_input' from /usr/lib/ruby/1.8/irb.rb:70:in`start’ from /usr/lib/ruby/1.8/irb.rb:69:in `catch' from /usr/lib/ruby/1.8/irb.rb:69:in`start’ from /usr/bin/irb:13 Maybe IRB bug!! Is this really a bug or is it just a necessary product of calling from irb? I don’t really need or want this as a public method. I suppose I could just make it so Rdoc doesn’t document it, as it isn’t like it is going to hurt anything if called directly. -d