# Class extension

**URL:** <https://www.ruby-forum.com/t/class-extension/189486>\
**Category:** Ruby\
**Created:** [June 1, 2010, 5:47pm UTC](https://www.ruby-forum.com/t/class-extension/189486 "2010-06-01T17:47:56Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![dasch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b2d939/32.png) [@dasch](https://www.ruby-forum.com/u/dasch)\
**Post date:** [June 1, 2010, 5:47pm UTC](https://www.ruby-forum.com/t/class-extension/189486/1 "2010-06-01T17:47:56Z")

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Hello all, newcomer to Ruby here and have a quick question a shorthand  
version of extend. below is the folder structure I have.

track  
|  
| - folderA  
|  
| - temp.rb  
|  
| - track  
|  
| - temp.rb

in the temp.rb located in track it’s defined like so

module track

class track \< ::track  
\<snip…\>

end

Can someone help me understand this shortcut? Thanks in advance.