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What clean code is not, and what it is instead

Not code beautifying

• Code correctness

Not a set of mechanic rules

• Continuous thinking

• Half science, half art

  • continuous shaping the code

• Principles instead of rules

• Terms

• Violations are only 'code smells'

No numeric rules

• Only one numeric rule: it does 1 thing.

• 'Simple' instead of 'small'.

No boilerplate code templates

• Alway the best simplest direct solution

Not for code checkers

• Human readability, expressivity

Not matter of taste

• Quest for an optimal implementation

Not waste of time

• Aims to finish the code

• Refactoring is not evil

• Technical debt is evil

Not easy

• Self discipline

  • it is easy to know the rules but not easy to apply them to ourselves

  • easy to see other's bad code but not easy to recognize when we do them

• Long practice

The ultimate goals of clean code

The software product should be...

• Error free

• Finished

• Maintainable

We realize the goals through...

• Expressiveness

• Granularity

When is the code good?

If it is decidable whether it is good.

• It is a comparison

  • Specification vs. implementation

  • Declaration vs. definition

  • Names vs. code blocks {}

Single Responsibility Principle

SRP is the core rule of clean code.

Reading the code with clean code view

I see independent, named code blocks { }:

• Does every code block {} do what its name tells?

  • Class's/Method's full declaration vs. definition block {}

• For one code block, I do not care about anything else outside

  • Callers of the methods

  • Methods called from this code block

• For parent classes, I don't care about the children

  • OCP, SRP, spaghetti

• Does everything have a name?

  • Methods: No inline implementation

  • Classes: No low cohesive classes

Modifying the code with clean code view

Before modification

• Understand affected parts

• Check cleanness

• If not clean, refactor

Do modification

• Change names first

• Implement code