SOLID design Five design principles SOLID design 1

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SOLID design Five design principles SOLID design 1

SOLID design Five design principles SOLID design 1

SOLID, what is it? • Single responsibility principle • A class should have only

SOLID, what is it? • Single responsibility principle • A class should have only a SINGLE responsibility • Change in the specification on that responsibility should only affect this class • Open/close principle • Each class should be open for extensions (sub-classes), but closed for modifications • We should never need to modify an existing class • Liskov substitution principle • Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program. • Named after Barbara Liskov • Interface segregation principle • Many client-specific interfaces is better than one general purpose interface • Dependency inversion principle • Depend on abstractions, not on concretions SOLID design 2

SOLID, what is it used for? • The SOLID principles are used as a

SOLID, what is it used for? • The SOLID principles are used as a guideline • Designing systems • Refactoring systems • Detecting “smells” in code • Refactor until the code is SOLID design 3

Single responsibility principle • Based on cohesion • A class should do only one

Single responsibility principle • Based on cohesion • A class should do only one thing • Separation of concerns SOLID design 4

Open/close principle • Open for extensions • Sub-classes • Closed for modifications • New

Open/close principle • Open for extensions • Sub-classes • Closed for modifications • New functionality should be placed in sub-classes • Overriding methods from the base class SOLID design 5

Interface segregation principle • Many client-specific interfaces is better than one general purpose interface

Interface segregation principle • Many client-specific interfaces is better than one general purpose interface • Clients should not be forced to depend upon interfaces that they don't use SOLID design 6

Dependency inversion principle • Depend on abstractions, not concretions • Abstractions = interfaces •

Dependency inversion principle • Depend on abstractions, not concretions • Abstractions = interfaces • Concretions = classes • Loose coupling Figure from Robert C. Martin http: //www. objectmentor. com/resources/articles/Principles_and_Patterns. pdf SOLID design 7

References and further readings • Robert C. Martin Design Principles and Design Patterns, 2000

References and further readings • Robert C. Martin Design Principles and Design Patterns, 2000 • http: //www. objectmentor. com/resources/articles/Principles_and_Patterns. pdf • michas The S. O. L. I. D Object Oriented Programming (OOP) Principles, 2010 • http: //www. codeproject. com/Articles/60845/The-S-O-L-I-D-Object-Oriented-Programming-OOP-Prin • Design Principles • http: //www. oodesign. com/design-principles. html SOLID design 8

Design principles SOLID Design principles circle class CircleDesign principles SOLID Design principles circle class Circle
SOLID Design Principles SOLID Stands For Single responsibilitySOLID Design Principles SOLID Stands For Single responsibility
Solid Modeling In the solid modeling the solidSolid Modeling In the solid modeling the solid
SOLID WASTE Collection and Transportation SOLID WASTE SolidSOLID WASTE Collection and Transportation SOLID WASTE Solid
Solid Waste Management Types of solid waste SolidSolid Waste Management Types of solid waste Solid
Additive and Subtractive Solid Modeling Solid Modeling SolidAdditive and Subtractive Solid Modeling Solid Modeling Solid
Solid Solutions Dispersions Solid Solutions Dispersions solid dispersionSolid Solutions Dispersions Solid Solutions Dispersions solid dispersion