# Access Control confusion

**URL:** <https://www.ruby-forum.com/t/access-control-confusion/156702>\
**Category:** Ruby\
**Created:** [January 1, 2009, 2:53pm UTC](https://www.ruby-forum.com/t/access-control-confusion/156702 "2009-01-01T14:53:20Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Chang\_Min\_Jeon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/f9ae1b/32.png) [@Chang\_Min\_Jeon](https://www.ruby-forum.com/u/Chang_Min_Jeon)\
**Post date:** [January 1, 2009, 2:53pm UTC](https://www.ruby-forum.com/t/access-control-confusion/156702/1 "2009-01-01T14:53:20Z")

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I read Ruby U.'s Guide [http://www.rubyist.net/~slagell/ruby/](http://www.rubyist.net/~slagell/ruby/)  
created by Yukihiro M.

[http://www.rubyist.net/~slagell/ruby/accesscontrol.html](http://www.rubyist.net/~slagell/ruby/accesscontrol.html)

and i have a question about access control.  
Access Control section explain method following code.

> - def square(n)\*  
> |\* n \* n\*  
> |\* end\*

Object class has square method.

But it is not allowed access of square method following document.

We are not allowed to explicitly apply the method to an object:

ruby\>\* “fish”.square(5)\*  
_ERR: (eval):1: private method `square’ called for “fish”:String_

But it is operated when i write code above in ruby 1.8.7

What is the matter ?  
wrong document ?