Code smell & Refactoring Mamata Gelanee 

Code Smell are certain structures in the code that indicate violation of fundamental design principles and negatively impact design quality. Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. 

“A code smell is a surface indication that usually corresponds to a deeper problem in the system” - Martin Flower 

Design Principles Every OO Designer should have follow below design principle, failing to that leads to code smells in your software. Design Principles: - Single Responsibility - Open Close principle - Interface Segregation - Dependency Inversion principle - Liskov Substitution principle 

Levels of Code smell There are three levels of code smell: 1. Method level 2. Class level 3. Application level 

Bad smells in a code Long Method - Extract method Long class - Extract Class Long parameter list - Introduce Object parameter Primitive Obsession - Introduce Object parameter Duplicate Code (Don’t Repeat Yourself) - Create Template method 

Long Parameter List 

Primitive Obsession 

Duplicate code 

Switch statements Replace conditional with polymorphism 

Oddball Solution Move method or Move class 

Black sheep Move Method 

Refused Bequest 1. Throw exceptions 2. Push down method or field 

Speculative Generality Oh! We might need this feature in future Remedy: - Collapse Hierarchy - Inline class - Remove Parameter 

Quiz Long class 

Quiz Long Parameter list 

Questions? 

Thanks! Software Engineer, Mastercard Transaction solution pvt. Ltd., Vadodara - Gujarat AndiGeeky @MamataGelanee andigeeky.wordpress.com/ mamatagelanee07