Four Simple Principles to Write High‑Quality Code Every Time

Excellent code is hard to achieve; even with abundant books and coding standards, most projects produce low‑quality code.

The main cause is trying to follow too many rules at once, leading to overload and ineffective application.

Four Core Principles of Excellent Code

1. Single Abstraction Level

A function should operate at a single logical level; all statements belong to the same abstraction.

2. Minimize Indentation

Deep nesting creates confusing code. Research shows most people struggle with more than three nesting levels, so keep indentation shallow.

Use guard clauses, replace nested conditionals with guard statements, and flatten complex if‑else structures.

Return early to reduce nesting.

Merge branches with identical behavior.

Flatten the structure.

3. Clear Expressions

Code should be readable with minimal effort; the "readability theorem" states that understanding time should be as short as possible.

Clear expressions are a key part of this theorem.

4. Use Helper Classes to Split Responsibilities

Large classes with many methods indicate poor design. Like a busy leader needs assistants, a giant class should delegate unrelated tasks to helper classes.

Delegate functions that do not manipulate data, have clear inputs/outputs, or do not interact with external objects.

Conclusion

Understanding a function should take as little time as possible; write code that can be quickly grasped and continuously refactor dirty code into clean, maintainable code.