Clean Code

Question 1

What is SOLID in clean code ?

Answer 1

SOLID are 5 principles introduced by Robert C.Martin (referred to as “Uncle Bob”) to make code more understandable, flexible and easier to maintain.

Question 2

What are 5 SOLID principles ?

Answer 2

SRP : Single Responsibility Principle
OCP : Open/Closed Principle
LSP : Liskov Substitution Principle
ISP : Interface Segregation Principle
DIP : Dependency Inversion Principle

Question 3

What is SRP ?

Answer 3

Definition : A class must have only one job/responsibility.
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Why it matters : Making change on a class with a multiple tasks can impact other code.

Question 4

What is OCP ?

Answer 4

Definition : Software entities ( class , function , module ) should be open for extensibility but closed for modification
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Why it matters : you can extend functionnalities of a system without changing the existing code, which makes code more reusable and reduce impact of code changing.

Question 5

What is LSP ?

Answer 5

Definition : Objects of super class should be replaced with objects of child class without causing issues.
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Why it matters : Reusable code , a child class can be used in the same way as its parent class.
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=> if a child class cannot do all parent things we can replace the parent class with a new “third class” or “interface” so both the precedent parent and child class become child to a new parent class(or implements a common interface).

Question 6

What is ISP ?

Answer 6

Definition :
*Client should not be forced to depend on methods that they don’t use.
*A class should perform only actions that are needed to fulfill its role.
*Do not let interfaces become larger ,divide them into many small interfaces so each one of them perform a specific role.
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Why it matters :
*This principle aims at sippliting actions into smaller ones so that classes executes ONLY actions required from it.
=>More reusable code
=>Focusing on one aspect
=>Reduce coupling

Question 7

What is DIP ?

Answer 7

Definition :
*High level modules should not depend on low level modules .Both should depend on the abstraction.
*Abstractions should depend on details. Details should depend on abstraction.
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Keyword definitions:
High level module : Class that use the tool to execute the action.
Low level module : Class of tool needed to execute action.
Abstraction : interface used to connect both classes.
Details : How the tool works.
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Why it matters : Reduce dependency of high level class on low level class by introducing an interface.
=>Reduce coupling
=>Reusable code

Question 8

A good Resource for learning 5 SOLID and Programming in general :

Answer 8

https://medium.com/backticks-tildes/the-s-o-l-i-d-principles-in-pictures-b34ce2f1e898
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Also:
https://mmmake.com/en/blog/solid-principles-easily-explained/

Question 9

Clean Code Summary

Answer 9

See Word Doc