Practical Object-Oriented Design: An Agile Primer Using Ruby
The Complete Guide to Writing Maintainable, Manageable, Pleasing, and Powerful Object-Oriented Applications

Object-oriented programming languages exist to help you create beautiful, straightforward applications that are easy to change and simple to extend. Unfortunately, the world is awash with object-oriented (OO) applications that are difficult to understand and expensive to change. Practical Object-Oriented Design, Second Edition, immerses you in an OO mindset and teaches you powerful, real-world, object-oriented design techniques with simple and practical examples.

Sandi Metz demonstrates how to build new applications that can “survive success” and repair existing applications that have become impossible to change. Each technique is illustrated with extended examples in the easy-to-understand Ruby programming language, all downloadable from the companion website, poodr.com. Fully updated for Ruby 2.5, this guide shows how to

Decide what belongs in a single class

Avoid entangling objects that should be kept separate

Define flexible interfaces among objects

Reduce programming overhead costs with duck typing

Successfully apply inheritance

Build objects via composition

Whatever your previous object-oriented experience, this concise guide will help you achieve the superior outcomes you’re looking for.

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